Schools across the country have seen threats go up this week. That includes right here in Southern California.
Police brought in the K9s that are trained to detect explosives but didn't find anything.
Detectives were working to identify the sender of that email when on Tuesday another email was sent against the school.
Working together with the FBI, Baldwin Park police arrested the suspect who they say is a student at the school.
Meanwhile in Santa Ana, police have determined that it was a former employee who made threats against Mater Dei High School, a private Catholic school. In conjunction with the Diocese of Orange County, the decision was made to shut down the school for this week as Santa Ana police continue to investigate.
In a statement, Mater Dei said in part, "We at Mater Dei take all threats made to the school seriously… we have made the decision to close our campus and cancel all campus activities immediately through June 3 as the Santa Ana Police Department continues their investigation."
It is not known if any arrests have been made at this time.