While Amanda and her friend visit an ethnically widely mixed school, a driving-by car fires at a class room and kills generally liked maths teacher Pete Delvecchio, principal Wallace Morrison was in the room but unhurt. Assistant D.A. Susan Turner, in charge of juvenile crime and well-reputed, having lost her husband at a kid's hands, investigates with the Sloans but starts on the premise it must be a teenager. The car is identified as belonging to Korean pupil Tommy Parks, who has a mild record but a good home and character, even an alibi, yet Turner arrests him, tenaciously even after Mark shows the ballistics suggest another fatal shooter and bails the boy out, she listens only when LAPD forensics confirm he's right. Pretending to be looking for mechanics, Jesse finds out about nastier, black boys in auto-shop then and against Tommy. Steve finds Delvecchio lied on his resume. When Inspector Michaels takes over the car shooter's investigation on Washington's authority, the Sloans ...