The call came into the San Diego’s 911 system around 3:30 a.m. Saturday: Could officers check on the safety of a teenage boy standing outside Torrey Pines High School in the affluent Carmel Valley neighborhood?

Minutes later, a 15-year-old teenager lay dying in a parking lot in front of the school. The police shot him, they said later, after he ignored multiple requests to drop a weapon — later determined to be a BB gun — that he was pointing at responding officers.

On Monday, Mike Holden, an acting captain with the San Diego Police Department, said that the teenager, who placed the call that sent officers to the school in the first place, had a suicide note with him that was recovered after he was shot.

The note indicated that the 15-year-old “had planned the incident that resulted in his death,” Captain Holden said.