A jury has found 17-year-old Phillip Sam guilty of first-degree murder and 12 counts of aggravated assault.

Sam opened fire on a group of teens last October near Martin Luther King, Jr. Park, killing 19-year-old Tyler Burns.

Sam, who was 16 at the time of the shooting, was on trial as an adult.

His attorney had argued that Sam had a gun because he feared he would be confronted by violent gang members, but prosecutors said Sam had set out to kill someone that day.

Sam is being held in the Laramie County Jail on $250,000 cash bond.  His sentencing date has yet to be scheduled.