UPS employee who reportedly threatened mass murder arrested. Cops say he had body armor, nine guns, and 20K rounds of ammo.

Police arrested a UPS employee who allegedly threatened to commit a mass shooting at the Sunnyvale, California, location where he worked, and they found that he was heavily armed and apparently ready to carry out the attack soon, according to CNN.

The Sunnyvale Department of Public Safety began investigating 32-year-old Thomas Andrews on Sunday after getting a report that Andrews sent texts to his boss expressing an intent to commit a mass shooting. Police began searching for him after finding that he had five guns registered.

Late Sunday night, officers found Andrews driving, but he fled. Police were able to apprehend him, with assistance from California Highway Patrol.

Upon searching Andrews' home, police said they found 20,000 rounds of ammunition, five rifles, a shotgun, three handguns, and body armor. Andrews had packed up several bags of ammo and placed them near his door, authorities said.

Sunnyvale Police Capt. Dan Pistor said Andrews was upset at his employer, according to KNTV-TV, but he did not elaborate on what the specific conflict was.

"He alluded to a mass shooting in his text messages," Pistor said, according to USA Today. "I definitely think we avoided a tragedy."

UPS did not provide any details in a statement issued to CNN, which simply said the company was cooperating with authorities on the investigation.

Andrews was arrested on suspicion of evading police, driving under the influence, and several weapons violations. He is in Santa Clara County Jail on $500,000 bail.