BREA, Calif. (AP) — A Southern California high school student who posed with a rifle and posted social media messages alluding to shooting people on campus has been arrested on suspicion of making criminal threats.

Police in the Orange County city of Brea say the boy's arrest Wednesday came after a concerned father saw the posts while monitoring his daughter's online activity.

Investigators say the unnamed suspect is a 16-year-old who attends Brea Olinda High. Police say the posts in question were made about seven weeks ago.

KCBS-TV reports (http://cbsloc.al/2pVN8w8 ) school officials sent a letter to parents reassuring them that the campus is safe and there is no threat to students.

Detectives praised the father for bringing the social media posts to their attention.