The incident happened just before 11:00 a.m. Wednesday along the Thun Trail in Cumru Township, Berks County.
Officials say three teens attempted to rob a 65-year-old man who was riding his bike along the trail.
The teens knocked the man off his bike and two of them started attacking the man.
The man then pulled a gun and shot two of the teens, one fatally.
The wounded teen is in the hospital with apparent non-life-threatening injuries.
The third teen has been committed to the Youth Detention Center.
After questioning, police released the 65-year-old man from custody.
Cumru police continue to investigate.
