Instructions

This map shows the intersection of states where mass shootings take place and the gun laws that are in place in those states. Above the map, you can select the type of law you would like to map. (The state will be filled in with blue if the law is in place there. In the case that you select 'lawtotal', the darker the shade of blue in the state, the more gun laws that state has in place.) If you are not sure what the law's variable name means, you can check in the table at the bottom of the page to find the law you would like to map. You can also select which year you would like to view with the dropdown menu. States with a heavier outline are state where a mass shooting occurred. If you select 'lawtotal' to view the total number of gun-related laws in the state, you can click on the state, and the names of all the laws in that state will appear next to the map.


A Note About Sources: The data on which states had mass shootings in each year came from Wikipedia. You can view the Wikipedia page for the mass shootings from each year below the map. The data about the gun laws in each state over the years came from a project by the Boston University School of Public Health. The D3 JavaScript library was used to generate these graphics. This page was styled using Bootstrap. See all my code for this project here.



Law type: Year:


Interesting observations

Some laws seem to be quite ubiquitous. If we look at the most popular laws and how many states they occur in, they are:

However, if we look at the coincidence of these laws, it's actually somewhat atypical that they all co-occur:

Missing five laws Missing four laws Missing three laws Missing two laws Missing one law
New Hampshire
Vermont
Rhode Island Alaska
Idaho
Maine
Montana
Alabama
Delaware
North Dakota
South Dakota
Arizona
Connecticut
Florida
Georgia
Hawaii
Indiana
Kansas
Louisiana
Maryland
Mississippi
Missouri
New Jersey
Ohio
Pennsylvania
South Carolina
Tennessee
Utah
West Virginia
Wyoming

The 20 states that have all five of the most popular laws are: Arkansas, California, Colorado, Illinois, Iowa, Kentucky, Massachusetts, Michigan, Minnesota, Nebraska, Nevada, New Mexico, New York, North Carolina, Oklahoma, Oregon, Texas, Virginia, Washington, and Wisconsin.

Links to information on the mass shooting from that year

Key to law variable names

Variable Name Description States with this Provision
dealer All firearm dealers are required to have a state license. California, Hawaii, Massachusetts, New Jersey, Pennsylvania, Rhode Island, Washington
dealerh All firearm dealers that sell handguns are required to have a state license. Alabama, California, Connecticut, Delaware, Hawaii, Indiana, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Washington
recordsdealer Licensed dealers are required to keep and retain records of all firearm sales. These records must include (1) the name and address of the buyer and (2) the make, model, and type of firearm. California, Connecticut, Delaware, Illinois, Maine, Massachusetts, Michigan, Oregon, Pennsylvania, Rhode Island, Tennessee
recordsdealerh Licensed dealers are required to keep and retain records of handgun sales. These records must include (1) the name and address of the buyer and (2) the make, model, and type of handgun. California, Colorado, Connecticut, Delaware, Florida, Illinois, Maine, Maryland, Massachusetts, Michigan, New Jersey, New York, North Carolina, Oregon, Pennsylvania, Rhode Island, Tennessee, Vermont, Washington
recordsall Both private sellers and licensed dealers are required to keep and retain records of all firearm sales. These records must include (1) the name and address of the buyer and (2) the make, model, and type of firearm. California, Connecticut, Delaware, Illinois, Oregon, Rhode Island
recordsallh Both private sellers and licensed dealers are required to keep and retain records of handgun sales. These records must include (1) the name and address of the buyer and (2) the make, model, and type of handgun. California, Colorado, Connecticut, Delaware, Illinois, Maryland, Michigan, New Jersey, New York, Oregon, Pennsylvania, Rhode Island, Washington
reportdealer Licensed dealers are required to report all firearm sales records to the state. Must include gun and sale information and must be transmitted electronically or by mail (not just phoned in). California, Connecticut, Hawaii, Massachusetts, Oregon, Pennsylvania, Tennessee
reportdealerh Licensed dealers are required to report handgun sales records to the state. Must include gun and sale information and must be transmitted electronically or by mail (not just phoned in). California, Connecticut, Hawaii, Maryland, Massachusetts, Michigan, New Jersey, New York, Oregon, Pennsylvania, Tennessee, Washington
reportall All private sellers and licensed dealers are required to report all firearm sales records to the state. Must include gun and sale information and must be transmitted electronically or by mail (not just phoned in). California, Connecticut, Hawaii, Massachusetts, Oregon
reportallh All private sellers and licensed dealers are required to report handgun sales records to the state. Must include gun and sale information and must be transmitted electronically or by mail (not just phoned in). California, Connecticut, Hawaii, Maryland, Massachusetts, Michigan, New Jersey, Oregon, Pennsylvania, Washington
purge The law does NOT require that dealers purge their sales records within 60 days of the firearm purchase. This may apply to handgun sales records, long gun sales records, or both. California, Connecticut, Hawaii, Maryland, Massachusetts, Michigan, New Jersey, New York, Oregon, Washington
residential Dealers must have a commercial place of business; they cannot operate out of a home, car, etc. Massachusetts
theft Dealers must report any and all thefts of firearms from their businesses. California, Massachusetts
security At least one of the following is required for gun dealers: (1) No gun displays visible from the outside; (2) Guns must be stored in a specified manner after business hours; (3) Burglar alarms and/or security systems installed. California, Connecticut, Massachusetts, Minnesota, New Jersey, Pennsylvania, Rhode Island, West Virginia
inspection The law requires at least one annual inspection of gun dealerships by the police or other law enforcement personnel. This refers to a STATE inspection, not an ATF inspection. Massachusetts, Rhode Island
liability Dealers are held liable for damages caused by a gun that they knowingly sold to a person who is either prohibited from purchasing a firearm or who intends to use that firearm illegally. Connecticut, Pennsylvania
junkgun The law prohibits the sale of handguns that fail to meet one or more of the following requirements: (1) Passes drop testing and firing testing; (2) Passes a melting point test; (3) Possesses specific handgun safety features; (4) Appears on a list of approved handguns. This may or may not apply to private sellers. California, Hawaii, Illinois, Maryland, Massachusetts, Minnesota
waiting There is a mandatory minimum waiting period for purchase of any firearm from a dealer. No exemption for concealed carry or purchase permit holders. California, Hawaii, Illinois, Rhode Island
waitingh There is a mandatory minimum waiting period for purchase of a handgun (or handguns and assault weapons) from a dealer. No exemption for concealed carry or purchase permit holders. California, Hawaii, Illinois, Maryland, Minnesota, New Jersey, Pennsylvania, Rhode Island
permit All firearms may only be sold to and possessed by individuals with a valid license or permit to possess or carry firearms. This may or may not include requiring a firearm safety certificate and must apply to both licensed dealers and private sellers. California, Connecticut, Hawaii, Illinois, Massachusetts, New Jersey, Rhode Island
permith Handguns may only be sold to and possessed by individuals with a valid license or permit to possess or carry handguns. This may or may not include requiring a firearm safety certificate and must apply to both licensed dealers and private sellers. California, Connecticut, Hawaii, Illinois, Iowa, Maryland, Massachusetts, Nebraska, New Jersey, New York, North Carolina, Rhode Island, Washington
permitlaw Individuals must obtain a permit in order to purchase a firearm through a permit approval process that includes law enforcement personnel. This may not apply to the purchase of long guns. Connecticut, Hawaii, Illinois, Iowa, Maryland, Massachusetts, Nebraska, New Jersey, New York, North Carolina, Rhode Island, Washington
fingerprint All firearm purchasers must have their fingerprints taken either at the point of purchase or during their permit/license application. This may not apply to the purchase of long guns and may exclude purchases from private sellers. California, Connecticut, Hawaii, Maryland, Massachusetts, New Jersey, New York, Oregon, Tennessee
training Individuals must take part in safety training or testing in order to purchase a firearm, either at the point of purchase or as part of obtaining a firearm permit/license. This may not apply to the purchase of long guns. California, Connecticut, Hawaii, Maryland, Massachusetts, Rhode Island
registration Individuals must register all firearms with the state, including the manufacturer, make, model, and serial number. Registration records must be maintained permanently or indefinitely. Hawaii
registrationh Individuals must register their handguns with the state, including the manufacturer, make, model, and serial number. Registration records must be maintained permanently or indefinitely. Hawaii, Michigan, New York
defactoreg All purchased firearms are registered with the state because of a requirement that all gun sales involve the permanent or indefinite retention of a record including the manufacturer, make, model, and serial number of the firearm; or, there is registration of all firearms. California, Hawaii, Massachusetts
defactoregh All purchased handguns are registered with the state because of a requirement that all gun sales involve the permanent or indefinite retention of a record including the manufacturer, make, model, and serial number of the firearm; or, there is registration of all handguns. California, Hawaii, Maryland, Massachusetts, Michigan, New Jersey, New York, Pennsylvania, Washington
age21handgunsale You must be 21 to purchase a handgun, regardless of whether it is from a licensed dealer or private seller. No exemption for parental consent. California, Connecticut, Delaware, Hawaii, Iowa, Maryland, Massachusetts, Nebraska, New Jersey, New York, Ohio, Rhode Island, West Virginia
age18longgunsale You must be 18 to purchase a long gun, regardless of whether it is from a licensed dealer or private seller. No exemption for parental consent. Alaska, California, Connecticut, Florida, Hawaii, Iowa, Louisiana, Maryland, Massachusetts, Michigan, New Jersey, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, Texas, West Virginia, Wisconsin
age21longgunsaled You must be 21 to purchase a long gun from licensed dealers. May or may not apply to purchase from private sellers. No exemption for parental consent. Hawaii
age21longgunsale You must be 21 to purchase a long gun, regardless of whether it is from a licensed dealer or private seller. No exemption for parental consent. Hawaii
loststolen Firearm owners are required to report any and all loss or theft of their firearms. California, Connecticut, Delaware, Illinois, Massachusetts, New Jersey, New York, Ohio, Rhode Island
onepermonth Buyers can purchase no more than one handgun per month, even if they have a concealed carry permit. In order to bypass this restriction, the buyer must be able to demonstrate an extraordinary need for the additional handgun. This may or may not apply to purchases from private sellers. California, Maryland, New Jersey
felony Law prohibits firearm possession by people who have been convicted of a felony. Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Illinois, Iowa, Kansas, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Nebraska, Nevada, New Mexico, New York, North Carolina, North Dakota, Oklahoma, Oregon, Tennessee, Texas, Utah, Virginia, Washington, West Virginia, Wisconsin, Wyoming
violent Law prohibits firearm possession by people who have committed violent misdemeanors punishable by less than one year of imprisonment. California, Connecticut, Hawaii, Maryland, New York
violenth Law prohibits handgun possession by people who have committed violent misdemeanors punishable by less than one year of imprisonment. California, Connecticut, Hawaii, Maryland, New York
violentpartial Law prohibits firearm possession by people who have committed violent misdemeanors punishable by more than one year of imprisonment. California, Connecticut, Delaware, Hawaii, Illinois, Maine, Maryland, Massachusetts, Minnesota, New Jersey, New York, North Dakota, Oregon, Pennsylvania, South Dakota, West Virginia
invcommitment Law prohibits firearm possession by people who have been involuntarily committed for inpatient mental health treatment. Alabama, Arizona, Arkansas, California, Connecticut, Delaware, Hawaii, Illinois, Kansas, Maine, Maryland, Massachusetts, Minnesota, Nevada, New Jersey, New York, North Dakota, Ohio, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Utah, Virginia, Washington, West Virginia, Wisconsin
invoutpatient Law prohibits firearm possession by people who have been involuntarily committed for outpatient mental health treatment. Arizona, Connecticut, Delaware, Hawaii, Illinois, Massachusetts, Nevada, New Jersey, New York, Oregon, Rhode Island, Tennessee, Virginia, Washington, West Virginia, Wisconsin
danger Law prohibits firearm possession by people who have been deemed by a court to be a danger to themselves or others. Alabama, Arizona, Arkansas, California, Connecticut, Delaware, Hawaii, Illinois, Kansas, Maine, Maryland, Massachusetts, Minnesota, Nevada, New Jersey, New York, North Dakota, Ohio, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Utah, Virginia, Washington, West Virginia, Wisconsin
drugmisdemeanor Law prohibits firearm possession by people who have been convicted of a drug-related misdemeanor. Connecticut, Delaware, Hawaii, Illinois, Maryland, Massachusetts, Minnesota, Nevada, New York, Pennsylvania
alctreatment Law prohibits firearm possession by people who have received treatment for alcohol-related problems that exceeds a state-defined threshold. Hawaii, Kansas, Massachusetts, Minnesota, North Dakota, Wisconsin
alcoholism Law prohibits firearm possession by people who have received treatment for alcoholism that exceeds a state-defined threshold. Alabama, California, Missouri, Ohio, South Carolina, West Virginia
universal Both licensed dealers and private sellers must conduct background checks at point of purchase for all firearms. This may or may not include exemptions for buyers who have already undergone a background check for a concealed carry permit or other licensing requirements. California, Colorado, Connecticut, Delaware, Nevada, New York, Oregon, Rhode Island, Washington
universalh Both licensed dealers and private sellers must conduct background checks at point of purchase for handguns. This may or may not include exemptions for buyers who have already undergone a background check for a concealed carry permit or other licensing requirements. California, Colorado, Connecticut, Delaware, Maryland, Nevada, New York, Oregon, Pennsylvania, Rhode Island, Washington
gunshow Law requires background checks for all firearm sales at gun shows at point of purchase. This closes the gun show loophole for all firearm sales. California, Colorado, Connecticut, Delaware, Illinois, Nevada, New York, Oregon, Rhode Island, Washington
gunshowh Law requires background checks for handgun sales at gun shows at point of purchase. This closes the gun show loophole for handgun sales. California, Colorado, Connecticut, Delaware, Illinois, Maryland, Nevada, New York, Oregon, Pennsylvania, Rhode Island, Washington
universalpermit Individuals must undergo a background check to purchase any type of firearm, either at the point of purchase or through a license/permit application. This may or may not include exemptions for buyers who have already undergone a background check for a concealed carry permit or other licensing requirements. California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Massachusetts, Nevada, New Jersey, New York, Oregon, Rhode Island, Washington
universalpermith Individuals must undergo a background check to purchase handguns, either at the point of purchase or through a license/permit application. This may or may not include exemptions for buyers who have already undergone a background check for a concealed carry permit or other licensing requirements. California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Iowa, Maryland, Massachusetts, Michigan, Nebraska, Nevada, New Jersey, New York, North Carolina, Oregon, Pennsylvania, Rhode Island, Washington
backgroundpurge The law does NOT require that the state purge its background check records within 60 days of the firearm purchase or permit application. This may apply to background checks for handgun possession, long gun possession, or both. California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Iowa, Maryland, Massachusetts, Michigan, New Jersey, New York, North Carolina, Oregon, Washington
threedaylimit Law requires that individuals undergo a background check when purchasing at least some weapons from private sellers, and extends the period in which a background check can be completed beyond the federal three day limit. May or may not apply to the purchase of handguns and may or may not extend the period beyond three days for licensed dealers. California, Delaware, Hawaii, Illinois, Maryland, Massachusetts, North Carolina, Pennsylvania, Rhode Island, Washington
mentalhealth Background checks for private sales are required for at least some weapons and there is an explicit requirement for search of mental health records. This may or may not apply to sales by licensed dealers. California, Connecticut, Delaware, Illinois, Massachusetts, New York, Oregon, Pennsylvania, Washington
statechecks Law requires state to conduct its own background check, not just the NICS check, for all firearm sales or permit applications. If at the point of purchase, must apply to gun show sellers and licensed dealers and may also apply to all other private sellers; if at the point of permit application, must apply to all licensed dealers and private sellers. California, Colorado, Connecticut, Hawaii, Illinois, Massachusetts, New Jersey, Oregon, Rhode Island, Washington
statechecksh Law requires state to conduct its own background check, not just the NICS check, for handgun sales or permit applications. If at the point of purchase, must apply to gun show sellers and licensed dealers and may also apply to all other private sellers; if at the point of permit application, must apply to all licensed dealers and private sellers. California, Colorado, Connecticut, Hawaii, Illinois, Iowa, Maryland, Massachusetts, Michigan, Nebraska, New Jersey, North Carolina, Oregon, Pennsylvania, Rhode Island, Washington
ammlicense Law requires that ammunition vendors be licensed. This must apply to all vendors of handgun ammunition; it may or may not apply to vendors of long gun ammunition. Massachusetts, Washington
ammrecords Vendors must retain ammunition sales records. This must apply to sales records of all handgun ammunition; it may or may not apply to sales records of long gun ammunition. California
ammpermit All firearm ammunition may only be sold to individuals who have a valid license or permit for that ammunition. This may or may not include purchase of ammunition from private sellers. Connecticut, Illinois, Massachusetts
ammrestrict All restrictions that hold for purchase of firearms also hold for purchase of ammunition. Application to restrictions on handguns only or long guns only is OK. California, Connecticut, Delaware, Florida, Hawaii, Illinois, Maryland, Massachusetts, Nevada, New Jersey, New York
amm18 Individuals must be age 18 or older to purchase ammunition from any type of dealer. No exemption for parental consent. California, Connecticut, Iowa, Maryland, Massachusetts, Rhode Island, West Virginia
amm21h Individuals must be age 21 or older to purchase handgun ammunition from any type of dealer. No exemption for parental consent. California, Connecticut, Iowa, Maryland, Massachusetts, New Jersey, New York, Rhode Island, West Virginia
ammbackground Purchasers of any type of ammunition must undergo a background check, either at the point of purchase or when obtaining a permit for ammunition purchase. Connecticut, Illinois, Massachusetts
age21handgunpossess You must be 21 to possess a handgun. No exemption for parental consent. Exclusions for adult-supervised hunting, sporting, or training activities are OK. Exception for possession on private premises NOT OK unless minor required to be under adult supervision. Connecticut, Hawaii, Iowa, Maryland, Massachusetts, New Jersey, New York, Rhode Island
age18longgunpossess You must be 18 to possess a long gun. No exemption for parental consent. Exclusions for adult-supervised hunting, sporting, or training activities are OK. Exception for possession on private premises NOT OK unless minor required to be under adult supervision. Arizona, Connecticut, Florida, Hawaii, Massachusetts, Michigan, Nevada, New Jersey, Oklahoma, Rhode Island, Washington, Wisconsin
age21longgunpossess You must be 21 to possess a long gun. No exemption for parental consent. Exclusions for adult-supervised hunting, sporting, or training activities are OK. Exception for possession on private premises NOT OK unless minor required to be under adult supervision. Massachusetts
gvro Law must allow both family members and law officers to initiate an immediate process to confiscate firearms from individuals deemed by a judge to represent a threat to themselves or others. Law must require the surrender and confiscation of firearms, including authorization for a search and confiscation of the individual's residence. Must allow for temporary removal of weapons pending a court hearing. California, Washington
gvrolawenforcement Law allows law enforcement officers (but not necessarily family members) to initiate an immediate process to confiscate firearms from individuals deemed by a judge to represent a threat to themselves or others. Law must require the surrender and confiscation of firearms, including authorization for a search and confiscation of the individual's residence. Must allow for temporary removal of weapons pending a court hearing. California, Connecticut, Indiana, Washington
college Law bans gun carrying on college campuses, but concealed carry weapons may be allowed. No exemption for authorized faculty or staff, except security staff. Must include both public and private colleges. Arkansas, California, Colorado, Florida, Illinois, Louisiana, Massachusetts, Mississippi, Nebraska, New Jersey, New Mexico, New York, North Carolina, Oregon, South Carolina, Tennessee, Texas, Wyoming
collegeconcealed Law bans gun carrying on college campuses, including concealed carry weapons. No exemption for authorized faculty or staff, except security staff. Must include both public and private colleges. California, Florida, Illinois, Louisiana, Massachusetts, Nebraska, New Jersey, New Mexico, New York, North Carolina, South Carolina, Wyoming
elementary Law bans gun carrying in elementary schools and on their grounds, even for persons with a concealed carry permit. No exemption for authorized faculty or staff, except security staff (including school resource officers). Must include both public and private schools. Alaska, Arkansas, Colorado, Connecticut, Delaware, Florida, Idaho, Illinois, Indiana, Iowa, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Montana, Nebraska, Nevada, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Pennsylvania, South Carolina, Texas, Virginia, Washington, Wisconsin, Wyoming
opencarryh Law bans the open carry of handguns in all public places, even with a concealed carry or handgun carry permit. Exemptions for open carry in the home, on personal property, in vehicles, and for hunting, target shooting, and training are permissible. Florida, New York, South Carolina
opencarryl Law bans the open carry of long guns in all public places, even with a concealed carry or other permit. Exemptions for open carry in the home, on personal property, in vehicles, and for hunting, target shooting, and training are permissible. California, Connecticut, Florida, Hawaii, Illinois, Massachusetts
opencarrypermith Law bans the open carry of handguns in all public places without a permit. Exemptions for open carry in the home, on personal property, in vehicles, and for hunting, target shooting, and training are permissible. California, Connecticut, Florida, Georgia, Hawaii, Illinois, Indiana, Maryland, Massachusetts, Minnesota, New Jersey, New York, North Dakota, Oklahoma, Rhode Island, South Carolina, Tennessee, Texas, Utah
opencarrypermitl Law bans the open carry of long guns in all public places without a permit. Exemptions for open carry in the home, on personal property, in vehicles, and for hunting, target shooting, and training are permissible. California, Connecticut, Florida, Hawaii, Illinois, Massachusetts, Minnesota, New Jersey, Tennessee, Utah
permitconcealed Law requires a permit in order for an individual to carry a concealed weapon, or the law bans all concealed weapons. Alabama, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Illinois, Indiana, Iowa, Kentucky, Louisiana, Maryland, Massachusetts, Michigan, Minnesota, Montana, Nebraska, Nevada, New Jersey, New Mexico, New York, North Carolina, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Virginia, Washington, Wisconsin
mayissue Law provides authorities with discretion in deciding whether to grant a concealed carry permit, or the law bans all concealed weapons. California, Connecticut, Delaware, Hawaii, Maryland, Massachusetts, New Jersey, New York, Rhode Island
showing Law prohibits applicants from being approved for concealed carry permits unless they make a heightened showing, such as demonstrating a particular need to possess a concealed weapon, or law bans all concealed weapons. California, Delaware, Hawaii, Maryland, New Jersey, New York, Rhode Island
ccrevoke Law requires authorities to revoke a concealed carry permit under certain circumstances, or law bans all concealed weapons. Alaska, Arizona, Arkansas, California, Colorado, Florida, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Nebraska, Nevada, New Jersey, New Mexico, New York, North Carolina, Ohio, Oklahoma, Oregon, Pennsylvania, South Carolina, Tennessee, Texas, Virginia, Washington, West Virginia, Wisconsin, Wyoming
ccbackground Law requires that individuals undergo a background check when applying for a concealed carry permit, or law bans all concealed weapons. Alabama, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, Utah, Virginia, Washington, West Virginia, Wisconsin, Wyoming
ccbackgroundnics Law explicitly requires that individuals applying for a concealed carry permit must undergo a background check process that includes a check of the NICS database. Alabama, Arkansas, Colorado, Georgia, Hawaii, Illinois, Iowa, Kentucky, Louisiana, Michigan, Minnesota, Missouri, Nebraska, Nevada, New Jersey, North Carolina, North Dakota, Ohio, Pennsylvania, Washington, Wisconsin
ccrenewbackground Law requires individuals to undergo a background check in order to renew a concealed carry permit, or law bans all concealed weapons. Alabama, Arizona, Arkansas, California, Colorado, Connecticut, Georgia, Hawaii, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Nebraska, Nevada, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, South Carolina, South Dakota, Texas, Utah, Virginia, Washington, West Virginia, Wisconsin, Wyoming
assault Law bans the sale of both assault pistols and other assault weapons. California, Connecticut, Maryland, Massachusetts, New Jersey, New York
onefeature Law bans the sale of assault weapons, using a generic definition of assault weapons based on only one feature. California, Connecticut, New York
assaultlist Law bans the sale of assault weapons and includes in this ban a list of some of the banned weapons. California, Connecticut, Maryland, Massachusetts, New Jersey, New York
assaultregister Law bans the sale of assault weapons. Individuals who already own assault weapons included in this ban must register their weapons. California, Connecticut, New Jersey, New York
assaulttransfer Law bans the sale of assault weapons. Individuals who already own assault weapons included in this ban are prohibited from selling or transferring their weapons to others. California, Connecticut, Maryland, New York
magazine Law bans the sale of both assault pistol ammunition and other large capacity magazines. California, Colorado, Connecticut, Maryland, Massachusetts, New Jersey, New York
tenroundlimit Law bans the sale of all magazines with a capacity of more than 10 rounds of ammunition. California, Connecticut, Maryland, Massachusetts, New York
magazinepreowned No purchase or possession of large capacity magazines is allowed. Individuals who already own large capacity magazines included in this ban may be required to turn them in. California, New Jersey, New York
lockd All handguns must be sold with either an integrated or external lock. This applies to licensed dealers and may or may not apply to private sellers. California, Connecticut, Illinois, Maryland, Massachusetts, Michigan, New Jersey, New York, Pennsylvania, Rhode Island
lockp All handguns must be sold with either an integrated or external lock. This applies to all dealers. California, Connecticut, Massachusetts, New Jersey
lockstandards All handguns must be sold with either an integrated or external lock, which must meet state-specified standards or be otherwise approved by the state. California, Massachusetts, New York
locked All firearms in a household must be stored securely (locked away) at all times. Massachusetts
capliability Owner of gun is criminally liable if a gun is not stored properly, regardless of whether a child actually gains access to the gun. California, Maryland, Massachusetts, Minnesota
capaccess Owner of gun is criminally liable if a gun is not stored properly and a child gains access to the gun. California, Hawaii, Maryland, Massachusetts, Minnesota, New Jersey, Texas
capuses Owner of gun is criminally liable if a gun is not stored properly and the child uses or carries the gun. California, Connecticut, Delaware, Florida, Hawaii, Illinois, Iowa, Maryland, Massachusetts, Minnesota, New Hampshire, New Jersey, North Carolina, Rhode Island, Texas, Wisconsin
capunloaded Owner of gun is criminally liable regardless of whether the stored gun is loaded. Hawaii, Maryland, Massachusetts
cap18 Owner of gun is criminally liable if child under age 18 has access to the gun. California, Delaware, Massachusetts, Minnesota, North Carolina
cap16 Owner of gun is criminally liable if child under age 16 has access to the gun. California, Connecticut, Delaware, Florida, Hawaii, Maryland, Massachusetts, Minnesota, New Hampshire, New Jersey, North Carolina, Rhode Island, Texas
cap14 Owner of gun is criminally liable if child under age 14 has access to the gun. California, Connecticut, Delaware, Florida, Hawaii, Illinois, Iowa, Maryland, Massachusetts, Minnesota, New Hampshire, New Jersey, North Carolina, Rhode Island, Texas, Wisconsin
traffickingbackground The law prohibits the trafficking of firearms; that is, the purchase of firearm with the intent to re-sell the firearm, but without going through a background check process (or without the buyer already having gone through a background check to obtain a firearm license). An exception for transfer to relatives is acceptable. California, Massachusetts
traffickingprohibited The law prohibits the purchase of a firearm with the intent to re-sell to a prohibited person. It must apply to all firearms. We make no distinction between whether the trafficker (original purchaser) must actually know that the buyer is prohibited, must have reason to believe that the buyer is prohibited, must recklessly sell the firearm, or must intend to sell to a buyer who is prohibited, regardless of knowledge of the buyer's status. An exemption for sale to relatives is acceptable. California, Colorado, Connecticut, Delaware, Florida, Illinois, Massachusetts, Minnesota, New York, North Dakota, Ohio, Utah, Virginia
traffickingprohibitedh The law prohibits the purchase of a handgun with the intent to re-sell to a prohibited person. We make no distinction between whether the trafficker (original purchaser) must actually know that the buyer is prohibited, must have reason to believe that the buyer is prohibited, must recklessly sell the firearm, or must intend to sell to a buyer who is prohibited, regardless of knowledge of the buyer's status. An exemption for sale to relatives is acceptable. California, Colorado, Connecticut, Delaware, Florida, Illinois, Indiana, Massachusetts, Minnesota, Nebraska, New York, North Dakota, Ohio, Utah, Virginia
strawpurchase The law prohibits a straw purchase of any firearm; that is, no person may purchase a firearm on behalf of another person. An exemption for transfer to relatives is acceptable. California, Massachusetts
strawpurchaseh The law prohibits a straw purchase of handguns; that is, no person may purchase a handgun on behalf of another person. An exemption for transfer to relatives is acceptable. California, Maryland, Massachusetts, Pennsylvania
microstamp Either ballistic fingerprinting or microstamping is required for all new handguns sold in the state. For ballistic fingerprinting, it must apply to all handguns. For microstamping, it must apply at least to semi-automatic pistols. California
personalized Law has initiated a process to review implementation of a policy that requires new handguns to have a mechanism so that only the authorized user can operate the gun. Maryland, New Jersey
nosyg Use of deadly force is not allowed to be a first resort in public. This is sometimes referred to as a "stand your ground" law. There is a duty to retreat. Does not count as shoot first law if it only applies when person is in a vehicle. Arkansas, California, Colorado, Connecticut, Delaware, Hawaii, Idaho, Illinois, Maine, Maryland, Massachusetts, Minnesota, Nebraska, New Jersey, New Mexico, New York, North Dakota, Ohio, Oregon, Rhode Island, Vermont, Virginia, Washington, Wisconsin, Wyoming
preemption There is NO state law which preempts (prevents) local governments from regulating firearms. Complete or partial preemption is considered as preemption under this category. To be preemption, must be specific to firearm regulation. Constitutional preemption is considered preemption. Connecticut, Hawaii, Massachusetts, New Jersey, New York
preemptionnarrow There is no state preemption beyond the preemption of one area of regulation, such as firearm registration or concealed carry permitting. California, Connecticut, Hawaii, Massachusetts, Nebraska, New Jersey, New York
preemptionbroad There is no preemption, narrow preemption, or broad state preemption across multiple areas of regulation, but it is not complete. California, Connecticut, Hawaii, Illinois, Massachusetts, Nebraska, New Jersey, New York
immunity The state does not have a law that provides immunity to gun manufacturers for damages caused by their products or which prohibits the state or local government from filing lawsuits against gun manufacturer. Protections for gun dealers do not count. California, Connecticut, Hawaii, Illinois, Iowa, Maryland, Massachusetts, Minnesota, Nebraska, New Jersey, New Mexico, New York, Oregon, Rhode Island, Vermont, Wisconsin, Wyoming
mcdv Law prohibits firearm possession by people convicted of a misdemeanor crime of domestic violence if the victim is a spouse, ex-spouse, or cohabitating partner. F10 The law must apply beyond family members, unless family members are defined to include ex-spouses and cohabitating partners. Alabama, Arizona, California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Indiana, Iowa, Louisiana, Maine, Maryland, Massachusetts, Minnesota, Nebraska, Nevada, New Jersey, New York, Oregon, Pennsylvania, South Dakota, Tennessee, Texas, Utah, Vermont, Washington, West Virginia
mcdvdating Law prohibits firearm possession by people convicted of a misdemeanor crime of domestic violence regardless of the relationship to the victim. Arizona, California, Connecticut, Delaware, Hawaii, Illinois, Indiana, Maine, Maryland, Massachusetts, Minnesota, Nebraska, New Jersey, New York, Vermont, Washington, West Virginia
mcdvsurrender Law prohibits firearm possession by people convicted of a misdemeanor crime of domestic violence and also requires them to turn in the firearms they already have. California, Colorado, Connecticut, Hawaii, Illinois, Iowa, Massachusetts, Minnesota, New Jersey, New York, Pennsylvania, Tennessee
mcdvsurrendernoconditions There are no additional conditions on the requirement that MCDV offenders turn in their firearms. No additional finding is necessary. California, Colorado, Connecticut, Hawaii, Massachusetts, Minnesota, New Jersey, New York, Pennsylvania, Tennessee
mcdvsurrenderdating The requirement that MCDV offenders turn in their firearms applies if the victim is a dating partner of the offender. California, Connecticut, Hawaii, Illinois, Massachusetts, Minnesota, New Jersey, New York
mcdvremovalallowed Law enforcement officials are authorized to remove firearms from MCDV offenders. Hawaii, Minnesota, New Jersey, Washington
mcdvremovalrequired Law enforcement officials are required to remove firearms from MCDV offenders. Minnesota
incidentremoval Law enforcement officials are required to remove at least some firearms from the scene of a domestic violence incident. California, Hawaii, Illinois, Montana, Nebraska, New Jersey, Ohio, Oklahoma, Pennsylvania, Tennessee, Utah, West Virginia
incidentall Law enforcement officials must remove all firearms from the scene of a domestic violence incident. Firearms that can be removed cannot be restricted to only firearms used in the incident, firearms threatened in the incident, or firearms brandished in the incident. New Jersey
dvro Subjects of a domestic-violence related restraining order (DVRO) are not allowed to possess firearms. The law must apply to possession, and not just purchase of firearms. Application to handguns only is acceptable. The law must apply beyond family members, unless family members are defined to include ex-spouses and cohabitating partners. Alabama, California, Colorado, Connecticut, Delaware, Florida, Hawaii, Illinois, Iowa, Louisiana, Maine, Maryland, Massachusetts, Minnesota, Nevada, New Hampshire, New Jersey, New York, North Carolina, Oregon, Tennessee, Texas, Utah, Virginia, Washington, West Virginia, Wisconsin
dvrodating Subjects of a DVRO are not allowed to possess firearms and the prohibition applies if the subject is a dating partner of the petitioner. California, Connecticut, Delaware, Hawaii, Illinois, Louisiana, Maryland, Massachusetts, Minnesota, New Hampshire, New Jersey, New York, North Carolina, Texas, West Virginia, Wisconsin
exparte Subjects of a temporary (ex parte) restraining order are not allowed to possess firearms. California, Connecticut, Hawaii, Illinois, Massachusetts, New York, North Carolina, Texas, Washington, West Virginia
expartedating The prohibition on firearm possession by subjects of an ex parte restraining order applies if the petitioner is a dating partner of the DVRO subject. California, Connecticut, Hawaii, Illinois, Massachusetts, New York, North Carolina, Texas, West Virginia
dvrosurrender Subjects of a DVRO are not allowed to possess firearms and are required to surrender the firearms that they already possess. California, Colorado, Connecticut, Hawaii, Illinois, Iowa, Maryland, Massachusetts, Minnesota, New Hampshire, New Jersey, New York, North Carolina, Tennessee, Washington, Wisconsin
dvrosurrendernoconditions There are no additional conditions on the requirement that DVRO subjects turn in their firearms. No additional finding is necessary. California, Colorado, Connecticut, Hawaii, Illinois, Maryland, Massachusetts, Minnesota, New Hampshire, New Jersey, New York, North Carolina, Tennessee, Wisconsin
dvrosurrenderdating The requirement that DVRO subjects turn in their firearms applies if the subject is a dating partner of the petitioner. California, Connecticut, Hawaii, Illinois, Maryland, Massachusetts, Minnesota, New Hampshire, New Jersey, New York, North Carolina, Wisconsin
expartesurrender Law requires subjects of an ex parte DVRO to turn in their firearms. California, Connecticut, Hawaii, Illinois, Massachusetts, New York, North Carolina, Washington
expartesurrendernoconditions Law requires subjects of an ex parte DVRO to turn in their firearms and there are no additional conditions on this requirement. No additional finding is necessary. California, Connecticut, Hawaii, Illinois, Massachusetts, New York, North Carolina
expartesurrenderdating Law requires subjects of an ex parte DVRO to turn in their firearms and this requirement applies if the subject is a dating partner of the petitioner. California, Connecticut, Hawaii, Illinois, Massachusetts, New York, North Carolina
dvroremoval Law requires law enforcement officials to remove firearms from people subject to a domestic violence-related restraining order. California, Massachusetts, Minnesota, New Jersey
stalking Law prohibits firearm possession by people who have been convicted of a stalking offense. Arizona, California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Indiana, Maryland, Massachusetts, Minnesota, New Jersey, New York, Pennsylvania, Vermont, Wisconsin