Police Make Arrest In Threat Against Las Lomas High School

WALNUT CREEK, CA — An arrest was made in connection with a recent threat against Las Lomas High School, Walnut Creek police said Thursday.

Shortly after noon on Friday, Feb. 10, staff from Las Lomas High School reported they received a phone call threatening a shooting on campus. Walnut Creek police responded and had students and staff shelter in place while the campus was thoroughly searched for any threats. No weapons were found on campus, and the lockdown was lifted.

Detectives immediately began investigating possible leads as to who may be responsible for the threat. Detectives identified Demoni Costello, 18, from Lathrop, as the person believed to be responsible for the threat, Walnut Creek police Lt. Holley Connors said in a news release.

Detectives secured a warrant for Costello’s arrest on suspicion of felony criminal threats and a misdemeanor for causing a false emergency report, Connors said.

Costello was taken into custody Thursday and booked into the Contra Costa County jail in Martinez, where his bail was set at $27,000.

"Follow-up investigation is still being conducted to confirm there are no other people involved in this threat; at this time, there is no additional information available," Connors said.

Authorities asked anyone with any information to call the Walnut Creek Police Department at 925-943-5844 or the anonymous tip line at 925-943-5865.