BREA (CBSLA) — A Brea high school student was arrested Wednesday on suspicion of making criminal threats.

A concerned father monitoring his teenage daughter’s social media activities when he came across posts made by a teenage boy holding a rifle, investigators said.

READ MORE: Scott Peterson Resentenced To Life In Prison In Pregnant Wife’s Slaying

“The postings were made approximately 7 weeks ago and included threatening messages that alluded to shooting people at school,” according to a police press release.

Investigators said the student is 16-year-old, who attended Brea Olinda High School.

READ MORE: Toby, Tik Tok's Baseball-Loving Beagle, Given VIP Tour Of Dodger Stadium

Brea police said it has been working with the Brea Olinda Unified School District to assure parents and students that appropriate action has been taken, and the campus is safe.

Superintedent Brad Mason sent out an email to parents.

“Today the Brea Police Department received a report from a community member about a social media posting of a Brea Olinda High School student holding a weapon that included threatening comments about BOHS. The posting appeared on social media approximately seven weeks ago. Brea PD immediately informed the District, and we are working closely with the police as they continue their investigation. Police have arrested the student, and school disciplinary consequences have been administered. The purpose of this message is to assure you that appropriate measures have been taken, and we believe that the campus and students are safe,” Mason wrote in the email.

MORE NEWS: Thousands Of LAUSD Students Still Unvaccinated As Deadline Nears

Detectives said this was a great example of – if you see something, say something – and urged others to do the same.