MONTEREY PARK (CNS) - A Monrovia man was arrested today in connection with a series of telephoned threats that led to the lockdowns of various  Southland schools, hospitals and a mall.

Gerardo Cortez, 26, was arrested at his home at around , according to Los AngelesCounty sheriff's Capt. Mike Parker. He was booked for five counts of felony making criminal threats and five counts of false report of an emergency.

His bail was set at $250,000. He is due for a court appearance on Thursday.

The most recent threat allegedly occurred on Thursday at ArcadiaHigh School: an anonymous call saying someone had a gun on the campus. On Sept. 10, NorthviewIntermediateSchool and adjacent DuarteHigh School, which are on the same campus, were placed on lockdown, according to deputies at the sheriff's TempleStation.

On Sept. 9, the Covina Police Department allegedly received a call at around from an anonymous male who said he was at “CitrusMedicalCenter” and had an AK-47 “and was going to start shooting people.”

A similar telephone call shut down a middle school in Monrovia about the same time.

“Investigators saw the obvious pattern ... a lot of people were frightened ... thousands were at least inconvenienced,” Parker said. “People trying to go shopping were terrorized by these phone calls.”

The FBI was among the agencies that took part in the investigation, along with police from Arcadia, Duarte, Glendora, Monrovia, Covina and West Covina.

Parker said “advanced technology” was used to track down the suspect, although he did not elaborate. He also said it was not immediately known if the suspect ever intended to carry out any of his threats.