By CBSBoston.com Staff

WORCESTER (CBS) – A Worcester police officer shot and killed a heavily armed man who threatened to detonate a bomb early Wednesday morning.

It started around 10:40 p.m. Tuesday when the man, later identified as 31-year-old Phet Gouvonvong, called 911 from Grafton Street.

According to Worcester District Attorney Joe Early, Jr., Gouvonvong was wearing body armor and appeared to be armed with an assault rifle and an explosive device with wires. He was also carrying a backpack.

Negotiations began, the area was sealed off by police and the SWAT team was brought in.

“They were trying to talk to him and it just kept getting worse,” said witness Anita Perez. “At the end you could hear him escalating, he was screaming at the cops.”

In this image from a cell phone, Worcester police say a heavily armed man faced off with a SWAT team on Grafton Street April 20. (Courtesy image)

Around 12:05 a.m., Early said Gouvonvong “got agitated,” made a move towards police and several shots were fired. Gouvonvong died at the scene. The district attorney said investigators later found Gouvonvong also had a handgun and several rounds of ammunition.

“I don’t know what he was saying, he was yelling at the police and all of a sudden you heard, three, four gunshots,” Perez said.

The Worcester Police officer who fired the shots has not been identified. Lt. Sean Murtha told reporters he has been put on administrative leave.

The bomb squad and investigators started searching Gouvonvong’s apartment late Wednesday morning.

Early could not confirm yet if the device Gouvonvong had was definitely a bomb.

“The negotiator, the dispatcher was on the phone with this man for an extended period of time, and he was telling us that this bomb could and would go off if things occurred to happen to him. But I can’t get into the negotiations. She kept him on the phone for a long time doing her job,” Early said.

There’s no word yet on a motive, but the district attorney said there was no evidence linking it to the Derek Chauvin verdict.

Worcester Police shut down part of Grafton Street early Wednesday morning. (WBZ-TV)

The standoff rattled neighbors.

“As I was walking back to my bedroom, I heard two gunshots,” said Sarah Kobach, who lives in the area. “So I immediately went to my bedroom window over here so I can see. I already know the cops are out here because I can already see all the way out the road. So I came outside to see what was going on, and that’s when there were police.”

“It’s scary. It really is,” said neighbor Marcia Tagliaferro. “I’m glad [the police] took care of it.”

They are asking any witnesses to come forward, especially those who may have video of the incident. Anyone with information should call Worcester Police at 508-799-8651.

CBSBoston.com Staff