In one key respect, Ralph Yarl was fortunate. The wounds the 16-year-old suffered after being shot twice on April 13, 2023 by the owner of the house whose doorbell he rang, thinking it was where he was due to pick up his two younger brothers, did not prove fatal.

Others who made similar mistakes have died. Take Renisha McBride, who sought help after wrecking her car in a Detroit suburb in 2013 or Carson Senfield, who entered the wrong car in Tampa – thinking it was his Uber – on his 19th birthday. And then there is the case of 20-year-old Kaylin Gillis, a passenger in a car that turned around in a driveway in upstate New York on April 15, 2023. What these young people have in common is that they were killed in accidental encounters with armed property owners.

As a scholar who has studied America’s love affair with guns and lethal self-defense, I have explored the history of laws that selectively shield citizens from criminal responsibility when they use force and claim self defense. Since 2005, these “Stand Your Ground” laws have spread to around 30 states, transforming the U.S.‘s legal landscape.

While pre-existing justifiable use of force laws allowed the use of lethal force for self defense in some circumstances, they required that people first try to retreat from a perceived threat if it was safe to do so or to seek a non-lethal solution to a hostile encounter. Stand Your Ground laws, meanwhile, authorize defensive violence without a duty to retreat, wherever a person may legally be. Some also expand the circumstances in which someone could use lethal force to defend property.

Although the laws appear to apply to all law-abiding citizens, research shows that they are not equitably enforced, and that they may be emboldening property owners to shoot first and question their actions later, even when there is no real threat of harm.

Certainly that seems to be the case with the shooting of Yarl. The wounding of the Black teen, who was simply trying to pick up his siblings, generated widespread outrage, especially when Kansas City Police Chief Stacey Graves suggested that investigators would consider whether the shooter – an 84-year-old white man – might have recourse to the state’s Stand Your Ground law as a defense against prosecution.

Given that the encounter took place on the shooter’s property, there is a possibility the shooter could find legal protection in the “Castle Doctrine”, which allows someone to use reasonable force – without first trying to retreat – in self-defense in their home. But he would still have to show reasonable cause for firing two shots at the unarmed teen standing at his front door.

Defining 'reasonable’ force

It seems that in the case of Yarl, state prosecutors believe that the bar of reasonable cause was not met. Andrew D. Lester, the homeowner, has since been charged with two counts: assault in the first degree and armed criminal action.

This does not preclude the defense from invoking Lester’s right to “Stand his Ground” and use force in self defense, if his lawyers can show Lester truly believed Yarl posed a real threat.

Missouri’s Stand Your Ground law, in place since 2016, removes the duty to retreat anywhere a person may legally be, even beyond one’s “castle.” But you still need to prove that force is used reasonably, that it was not carried out in aggression or anger, and that there was a genuine fear for your life.

Indeed, the resolution of cases like the Yarl shooting turn on a highly subjective reckoning of what counts as reasonable force, and on which side – prosecution or defense – bears the burden of proof.

Traditional use of force laws place that burden on the alleged self-defender, who must prove that their actions were reasonable. But some other “Stand Your Ground” states, like Florida, remove the burden of proof from the defense, placing it on the prosecution.

This means that the prosecution must prove that the alleged self-defender was truly fearful when they used force. In some instances, as in the shooting of Carson Senfield after he tried to enter a car he misidentified as his Uber, the Stand Your Ground law becomes a shield against prosecution. No charges have been filed in this case, in large part because there were no other witnesses to contradict the shooter’s claim that he was in fear for his life when Senfield tried to enter his car.

Increase in gun homicides

Contrary to the claims of the framers and promoters of Stand Your Ground laws, there is scant empirical evidence that the laws prevent crime. In fact, multiple studies show just the opposite.

Research on public health and crime reveals a pernicious effect of Stand Your Ground laws on public safety, showing a correlation with increased rates of gun homicide. One study, which includes an assessment of Missouri’s law, found that the passage of “Stand Your Ground” laws correlates with an 8% to 11% increase in firearm homicide rates.

An analysis of Stand Your Ground cases in Florida, carried out by gun violence prevention group Everytown for Gun Safety, addressed the way removal of the duty to retreat encourages violent escalation; researchers suggested that over half the cases could have been resolved without loss of life.

Further, recent scholarship shows how Stand Your Ground laws intensify existing racial injustices in the U.S. criminal legal system. A study by the think tank Urban Institute found significant discrepancies in the rate at which homicides in Stand Your Ground cases were deemed justified, depending on the race of the shooter and the race of the deceased. White shooters were significantly more likely to to be exonerated when their victim was Black, suggesting that – particularly in states with Stand Your Ground laws – white people may feel more legally empowered to use lethal force and avoid prosecution, as long as their victims are Black.

Encouraging armed citizenry

In the case of Ralph Yarl, the possible presence of racial bias has not escaped the attention of Kansas City prosecutors. Lester’s grandson has described his grandfather as a QAnon devotee with “racist tendencies and beliefs” that likely prompted his violent reaction to Yarl’s presence on his doorstep.

Against the backdrop of historical legacies of racial bias in the U.S., Stand Your Ground laws intensify the risks of shooting deaths in an increasingly gun-saturated public. With laws that encourage armed citizens to use force against any perceived threat – real or imagined – even the most innocent mistakes and chance encounters can turn deadly.

Caroline Light is affiliated with Street Philosophy Institute (SPI) and the Center for Antiracist Research (CAR) at Boston University.