Well, his gun. [Note: the gun shown is not the gun not not shown.] Here’s the story from necn.com:
Authorities say an 18-year-old student was arrested after telling administrators at a Las Vegas high school that he left a rifle and ammunition in his car in a school parking lot. Clark County school police Lt. Ken Young says Joseph Patella was arrested Tuesday at Sierra Vista High School and charged as an adult with possessing a dangerous weapon on school property. Patella is a senior at the school. Young tells the Las Vegas Sun that Patella mentioned while talking with administrators that he had forgotten to take a .22-caliber rifle and bullets out of his car after target shooting on Monday night. Patella was booked at the Clark County jail and freed on $2,000 bail. The school wasn’t locked down during the incident.