WALNUT CREEK, Calif. (KRON) — Walnut Creek police have announced the arrest of an 18-year-old man in connection to a false active shooter report on Friday that led to Las Lomas High School being locked down. Demoni Costello of Lathrop was arrested on Thursday and booked into the Martinez Detention Facility where he is being held on $27,000 bail, according to a social media post from the Walnut Creek Police Department.

The arrest is in connection to an incident on Friday, Feb. 10 when shortly after noon Las Lomas school staff reported they received a phone call threatening a shooting on campus. Officers with the Walnut Creek PD responded while students and staff were asked to shelter in place. The campus was thoroughly searched but no weapons were found and no threat was determined.

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The lockdown was lifted. Officers launched an investigation and detectives were able to identify Costello as the person allegedly responsible for the threat, police said. A warrant was obtained for Costello’s arrest for felony criminal threats and a misdemeanor for causing a false emergency report.

A follow-up investigation is being conducted to determine if there were other people involved, police said.