Two teens arrested in fatal San Mateo shooting FacebookTwitterEmail Two 16-year-old boys were arrested Monday on suspicion of killing a man outside the San Mateo Adult School, police said.The Chronicle Two 16-year-old boys were arrested Monday on suspicion of killing a man outside the San Mateo Adult School, police said. The 19-year-old man was shot just before 9 p.m. Friday at the Poplar Avenue campus in San Mateo. Police suspect the teens had argued with the man and the confrontation escalated, said San Mateo Police Officer Alison Gilmore, a department spokeswoman. Police suspect someone fired “several gunshots,” hitting the man in the torso as he sat in the driver’s seat of a parked vehicle, police said. The man, who has not been identified, was taken to a hospital where he died.