San Diego police say a 15-year-old boy left a suicide note before he was killed by officers after pointing a BB gun at them in a high school parking lot in the dark.

Assistant Police Chief Brian Ahearn told The Associated Press on Monday that police found the note on the Torrey Pines High School student and believe he called police and pointed the BB gun at them so he would be shot.

Police say the boy called 911 shortly before 3:30 a.m. to ask officers to check on the welfare of an unarmed boy in front of the school.

Investigators later determined he was referring to himself.

Police are still investigating.