The murder trial of a Montana man who shot and killed 17-year-old German exchange student Diren Dede in his garage tested a state law that gives a person the right to use force or threaten to use force to protect his or her own home from unlawful entry or attack, particularly a provision known as "stand your ground." Markus Kaarma unsuccessfully invoked the law in his defense, saying he was protecting his family and property. He was convicted of deliberate homicide Wednesday. Here's a brief explanation of the law and controversy surrounding it.


Montana's self-defense law has been on the books in some form since the 19th century. In 2009, it was amended to eliminate the restriction that a person was justified in using force only when entry is made or attempted "in violent, riotous, or tumultuous manner." It also was changed to state that a person who is threatened with physical harm has no duty to retreat or summon law enforcement assistance prior to using force. Shortly after Dede's death, a state legislator proposed legislation striking the 2009 changes, arguing they encourage vigilante justice. Gary Marbut, of the Montana Shooting Sports Association, has said it is premature to say the law needs to be fixed. Marbut, who helped draft the 2009 changes, had argued that if Kaarma was convicted, it would prove the law was working fine.


Montana is just one of about half the 50 U.S. states that have enacted "stand your ground laws," starting with Florida in 2005. The laws have strong backing from gun rights groups, including the powerful National Rifle Association. But the Florida's law came under intense scrutiny during the trial of neighborhood watchman George Zimmerman, who was the acquitted in the 2012 shooting death of unarmed black teenager Trayvon Martin. Other cases have called into question laws in Minnesota, Colorado, North Carolina and other states.