The common law principle of “castle doctrine” says that individuals have the right to use reasonable force, including deadly force, to protect themselves against an intruder in their home. This principle has been codified and expanded by state legislatures.
In the 1980s, a handful of state laws (nicknamed “make my day” laws) addressed immunity from prosecution in use of deadly force against another who unlawfully and forcibly enters a person’s residence. In 2005, Florida passed a law related to castle doctrine, expanding on that premise with “stand your ground” language related to self-defense and duty to retreat. Florida’s law states “a person who is not engaged in an unlawful activity and who is attacked in any other place where he or she has a right to be has no duty to retreat and has the right to stand his or her ground and meet force with force, including deadly force, if he or she reasonably believes it is necessary to do so to prevent death or great bodily harm to himself or herself or another or to prevent the commission of a forcible felony.”
Laws in at least 25 states allow that there is no duty to retreat an attacker in any place in which one is lawfully present. (Alabama, Alaska, Arizona, Florida, Georgia, Idaho, Indiana, Kansas, Kentucky, Louisiana, Michigan, Mississippi, Missouri, Montana, Nevada, New Hampshire, North Carolina, Oklahoma, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, Utah and West Virginia.) At least ten of those states include language stating one may “stand his or her ground.” (Alabama, Florida, Georgia, Idaho, Kansas, Kentucky, Louisiana, Oklahoma, Pennsylvania and South Carolina.)
Pennsylvania's law, amended in 2011, distinguishes use of deadly force outside one’s home or vehicle. It provides that in such locations one cannot use deadly force unless he has reasonable belief of imminent death or injury, and either he or she cannot retreat in safety or the attacker displays or uses a lethal weapon. Idaho’s law, passed in 2018, expanded the definition of justifiable homicide to include not only defending one’s home against an intruder, but also defending one’s place of employment or an occupied vehicle.
Self-defense laws in at least 23 states (Arizona, Arkansas, Colorado, Florida, Georgia, Idaho, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Montana, New Hampshire, North Carolina, North Dakota, Oklahoma, Ohio, Pennsylvania, South Carolina, Tennessee West Virginia and Wisconsin) provide civil immunity under certain self- defense circumstances.
Statutes in at least six states (Hawaii, Missouri, Nebraska, New Jersey, North Dakota and Tennessee) assert that civil remedies are unaffected by criminal provisions of self-defense law.
*In 2018, the Ohio House and Senate voted to override the Governor’s veto of House Bill 228. The bill places the burden of disproving a self-defense claim on the prosecution.
Additionally, some states (including Arizona, Arkansas, California, Florida, Kansas, Kentucky, Louisiana, Mississippi, North Carolina, North Dakota, Oklahoma, Pennsylvania, Rhode Island, South Carolina, Wisconsin, and Wyoming) have replaced the common law “reasonable person” standard, which placed the burden on the defendant to show that their defensive action were reasonable, with a “presumption of reasonableness,” or “presumption of fear,” which shifts the burden of proof to the prosecutor to prove a negative.