More than 30 states have laws that allow people to use deadly force if they have a reasonable fear for their life or property. But this week, a Montana jury said that type of law has its limits, finding a homeowner who shot a teenager in his garage guilty of deliberate homicide.
In the early hours of April 27, a motion detector alerted homeowner Markus Kaarma someone was in the garage of his home in Missoula, Mont. He went outside and almost immediately fired four shotgun blasts, killing 17-year-old Diren Dede, a German exchange student.
Prosecutors contended 30-year-old Kaarma was the aggressor and had purposefully lured an intruder into his garage to hurt him.
During the two-week trial, witness Tanya Colby testified to what Kaarma had told her just days before the shooting.
"He said 'I'm tired. I've been up for the last three nights with a shotgun wanting to kill some kids,' " Colby said.
Kaarma, his girlfriend and their infant son had been the victim of a burglary in their garage just days before the shooting. But Deputy Missoula County Attorney Karla Painter said Kaarma left his garage door open that night to exact vigilante justice.
"He had one thing on his mind, and that was revenge," Painter said.
Defense attorney Paul Ryan, however, argued Kaarma's use of deadly force was justified because he feared for his life and his family's safety.
"You shouldn't have to run out the back door, or lock up because the state wants to tell you to lock up," Ryan said. "It's my house. Not the burglar's house."
The jury disagreed and found Kaarma guilty of deliberate homicide.
Since Florida became the first of several states to expand so-called stand-your-ground laws outside the home in 2005, several cases have tested the boundaries of self-defense law.
Most famously, a Florida jury acquitted George Zimmerman — a neighborhood watch volunteer — in the shooting death of 17-year-old Trayvon Martin in 2012.
University of Montana law professor Andrew King-Ries says using deadly force is a valid defense in Montana against immediate threats in your home.
But he says if someone lures a thief into his garage, it's much harder to say he felt an immediate threat.
"Is it reasonable to use force to defend your house, when you've basically brought someone into your house?" King-Ries says "It's not like somebody's just suddenly there."
King-Ries also says a jury has to believe the person had a reasonable fear of assault. He says these types of cases are forcing a national conversation.
"We've seen stand-your-ground-type statutes; we've seen amendments to legislation across the country," he says.
And in a state with a strong history of supporting gun culture, a Montana jury's guilty verdict could indicate a change in how some residents view the role of guns in home defense.
Sentencing for Kaarma is scheduled for Feb. 11. He faces a minimum of 10 years in prison.