SUNNYVALE (CBS SF) – A United Parcel Service employee from Sunnyvale is in custody after police said he threatened a mass shooting at his workplace and had more than 20,000 rounds of ammunition at his home.

According to the Sunnyvale Department of Public Safety, 32-year-old Thomas Andrews was arrested following a pursuit on Sunday.

Authorities launched an investigation after receiving a report of Thomas sending texts threatening his employer of a mass shooting at the UPS facility in Sunnyvale where he worked, along with discovering he was the registered owner of four handguns and a rifle.

Late Sunday night, officers spotted Andrews in the area of Fair Oaks and Maude avenues. Police said Andrews led them on a chase onto Highway 101. The chase ended on the highway near Bailey Avenue in South San Jose and Andrews was taken into custody.

Police executed a search warrant at Andrews’ home in Sunnyvale and found the ammunition, along with high-capacity magazines, five tactical-style rifles, a shotgun, three handguns and body armor.

Andrews was booked into Santa Clara County jail on multiple charges, including making criminal threats, evading police, DUI and several weapons violations. It was not immediately clear when Andrews would appear in court.

His bail was set at $500,000, according to authorities.

Anyone with information regarding the case is asked to contact Detective Barron Renzi at (408) 730-7712.