INVER GROVE HEIGHTS, Minn. (AP) _ The third teen charged in a fatal melee involving rival gangs on a party bus in Inver Grove Heights has been arrested, more than three weeks after the shooting.

The boys, ages 16 and 17, are charged in juvenile court with second-degree assault and first-degree riot. Police haven't yet nailed down which teen fired the shot that killed 19-year-old Bill Ray Nobles outside a movie theater March 24.

Authorities say the rival groups involving 40 to 50 people argued on the bus and began fighting as they exited the vehicle. Nobles was killed a 16-year-old victim was wounded.

Police say the fight involved rival gang affiliation.