Federal agents and West Covina police had been conducting a drug investigation of a man when he was fatally shot Thursday by a West Covina police officer, authorities said Friday.

Emmanuel Alvarez, 27, was wearing a bulletproof vest and had a five pounds of methamphetamine in his car when two West Covina police officers stopped him on Azusa Avenue, just north of Merced Avenue, at about 3 p.m. Thursday, West Covina police Chief Frank Wills said.

Police said Alvarez was shot to death after he reached for a semiautomatic handgun.

“These were criminals that were going to go out in a blaze of glory,” Wills said. “They were all carrying semiautomatic guns and bulletproof vests.”

U.S. Immigration and Customs Enforcement, at the request of West Covina police, were conducting a joint investigation into Alvarez and the two other men riding in the car, said Virginia Kice, a spokeswoman with ICE.

Authorities identified those two as Fred Beltran, 23, and the dead man’s brother, Juan Carlos Alvarez, 37.

Wills said Alvarez and the two men were being investigated for “a narcotics violation and possession of illegal narcotics.”