Markus Kaarma, a 2003 Mercer Island High School graduate, former All-American swimmer and current Missoula, Mont. resident, was convicted of deliberate homicide Wednesday Dec. 17.

His case tested the limits of Montana’s self-defense and right to property laws.

According to news reports, Kaarma, 30, shot and killed German exchange student Diren Dede, 17, after catching Dede trespassing in his garage on April 27. Witnesses testified Kaarma fired four shotgun blasts at Dede, who was unarmed. Prosecutors said Kaarma baited Dede by leaving his garage door partially open and a purse filled with cash inside.

Kaarma faces a minimum penalty of 10 years in prison when he is sentenced Feb. 11.

Wednesday’s verdict came after several weeks of trial and months of international media attention – with both the German media and the German government following the trial’s progress.

At trial, neighbors testified that Kaarma’s girlfriend told them of the couple’s plans to bait an intruder and catch a burglar themselves because they believed police weren’t responding to area break-ins.

More than 30 U.S. states, including Montana, have laws expanding the right of people to use deadly force to protect their homes or themselves, some of them known as “stand your ground” laws. The self-defense principle is known as the “castle doctrine,” which grants people the right to defend their homes against attack.

Kaarma’s lawyers argued that the “castle doctrine” allowed him to use deadly force to protect his home and family. This defense failed in the initial trial, though his attorneys say they plan to appeal.

At Mercer Island High School, Kaarma was an accomplished athlete in football, track and most notably, swimming, winning Seattle’s 3A title in the 50 freestyle swim, and swimming the anchor leg in a record setting 200 free relay and the Washington State champion 200 relay team.