The 12 people who were shot dead in a Virginia Beach government building have been remembered at a sombre news conference and prayer vigil in the city as officials sought to focus on those who died, and not the gunman.

Authorities named the assailant as 40-year-old DeWayne Craddock, who was employed for 15 years as an engineer with the city’s utilities department.

Police chief James Cervera declined to comment on a motive for Friday’s rampage in the Virginian coastal city, which ended with Craddock’s death following a gun battle with police.

City officials uttered his name just once and said they would not mention it again.

Local official Dave Hansen said he had worked for years with many of the dead, 11 of whom were city employees. The 12th was a contractor trying to obtain a permit.

Their names and photos were projected on a screen as Mr Hansen read aloud biographical information that included their hometowns and years of service.

“They leave a void that we will never be able to fill,” he said.

Virginia Beach ShootingVirginia State Police vehicles block a street near the scene of a shooting at at the municipal building (AP)

Chaplains and family assistance workers worked through the night to notify relatives – a job that Mr Hansen described as “the most difficult task anyone will ever have to do”.

One of the dead employees had worked for the city for 41 years.

Six worked in the same department as Craddock, though authorities have declined to say if anyone was specifically targeted or if the suspect had issued threats before. The victims were found throughout the building, on three floors, police said.

Authorities have said Craddock opened fire indiscriminately.

Four other people were wounded, including a police officer whose bulletproof vest saved his life.

The suspect was armed with a .45-caliber handgun with a noise suppressor, police said.

Virginia Beach ShootingVirginia governor Ralph Northam also attended the vigil (AP)

Mr Cervera said more weapons were found at the scene and at his home.

Officers also said the gunman made multiple legal firearm purchases recently, and the guns recovered at the scene were purchased legally.

The building was open to the public, but security passes were required to enter inner offices, conference rooms and other work areas. As a current employee, Craddock would have had the pass to enter the inner offices, Mr Hansen said.

Asked how secure the building was, the police chief said that government buildings must balance access with security.

Virginia Beach ShootingMembers of Mount Olive Baptist Church pray near the site of the massacre (AP)

“It’s an open government building. Citizens have the right to access open government buildings. Employees have a right to access their work site,” he said.

Craddock was a professional engineer who had graduated from Denbigh High School in nearby Newport News in 1996 and joined the Army National Guard, according to a newspaper clip from the time.

He received basic military training and advanced individual training at Fort Sill, Oklahoma. He later graduated from Old Dominion University with a bachelor’s degree in civil engineering.

The 11 city employees who were killed were identified as Tara Welch Gallagher, Mary Louise Gayle, Alexander Mikhail Gusev, Katherine A Nixon, Ryan Keith Cox, Joshua A Hardy and Michelle “Missy” Langer, all of Virginia Beach; Laquita C Brown and Robert “Bobby” Williams, both of Chesapeake; and Richard H Nettleton of Norfolk and Christopher Kelly Rapp of Powhatan.

The 12th victim, Herbert “Bert” Snelling of Virginia Beach, was a contractor filling a permit.

Virginia Beach ShootingEleven of the 12 people killed were long-standing government workers (AP)

Craddock appeared to have had no felony record, which would have made him eligible to purchase guns.

Joseph Scott, an engineering technician with the department of public works, said he had worked with Craddock before and had a brief interaction with him on Friday. Mr Scott said he saw him in the men’s toilets about five minutes before the shooting.

“He was in there brushing his teeth, which he always did after he ate,” Mr Scott said.

“I said ‘Hey, how you doing? What are you doing this weekend?’ It was just a brief conversation.”

Mr Scott said he left for the day right after and learned of the shooting when a co-worker and then his son called him asking if he was OK.

“I couldn’t believe that it happened,” he said.

Mr Scott said he worked in a different division from Craddock, whom he described as quiet, polite and a “nice guy”. Mr Scott said he thought Craddock was in good standing at work and had never heard negative reports about him.

Mr Scott was among about 200 people who attended a Saturday prayer vigil for those killed.

Governor Ralph Northam also attended. “We grieve with you,” Mr Northam said. “We are all in this together.”

Mr Scott said he, his wife and several other people prayed for the shooter.

“He was a human too, and his family is hurting too,” he said. “He’s not evil … he was just another guy who had problems.”

Craddock’s neighbours said police swarmed their street in Virginia Beach. Some said he had lived there for at least 10 years.

Several neighbours said Craddock was a clean-cut member of the neighbourhood association board whose wife had left him some years ago.