A teenager was shot to death in a high school hallway as classes were about to resume after the winter break, and police arrested a fellow student found wandering a neighborhood a few blocks away, authorities said.
Police were trying to determine what prompted the shooting.
Witnesses said the gunman fired three shots at point-blank range, splattering blood on lockers at Foss High School and setting off panic. He did not appear to be aiming at anyone other than the victim.
The victim "got shot - bang - and he just fell," said sophomore Malcolm Clark. "He just froze and he fell backwards into the lockers."
The teenager suspected in the shooting was caught without incident about two hours later in a suburban area dotted with homes and shopping centers.
The gunman was identified as Douglas Chanthabouly, 18, who was booked for investigation of first-degree murder.
The shooter and victim were acquainted, but detectives did not know a motive. Police Chief Donald Ramsdell said Chanthabouly was being cooperative.