The 12 people killed after a man opened fire at the Virginia Beach Municipal Center in Virginia on Friday included decades-long employees of the city, officials said.

Their identities were released by City Manager Dave Hansen at a news conference on Saturday. "They leave a void that we will never be able to fill," he said.

Four others remained hospitalized on Saturday, three in critical condition and one in fair condition, authorities said.

A police officer was among the injured in the shooting, but the officer is doing well, having been saved by wearing a bulletproof vest, according to police.

Among those who died was Robert "Bobby" Williams, from Chesapeake. He was the longest-serving employee among the victims, having worked as a special projects coordinator for 41 years.

Laquita C. Brown, from the nearby city of Chesapeake, had been a right of way agent in the city's public works department for 4-1/2 years. She was the kind of person who would bring in cupcakes when people were having bad days at work and was never in a bad mood, said Danielle Cyr DeFrias, a friend who worked with her at a previous job.

"She lit up the office every single day," said DeFrias, who described Brown as a "bright spot in just about everybody's day.

"She was a very kind, loving soul who cared about her friends and family," DeFrias continued, adding Brown was very close to her mother and was a devout Jehovah's witness.

DeFrias said one of her last conversations with Brown came after DeFrias' brother died.

"She sat down with me and was very sympathetic and encouraging," DeFrias said. "She gave me such a feeling of encouragement and peace in a very sad time."

Other public works employees included Tara Welch Gallagher, from Virginia Beach, who served as an engineer for six years. Alexander Mikhail Gusev, also from Virginia Beach, worked as a right-of-way agent for nine years.

Christopher Kelly Rapp, an engineer from Powhatan, worked for the department for only 11 months, while Mary Louise Gayle, from Virginia Beach, served as a right-of-way agent for 24 years.

Katherine A. Nixon, from Virginia Beach, had been an engineer within the public utilities department for a decade. Richard H. Nettleton, from Norfolk, was also an engineer in the department for 28 years.

Nettleton always wore a jacket and tie to work and was a devoted husband a father, said Bob Sciacchitano, who knew Nettleton through the Hampton Roads Planning District Commission and considered him a longtime friend.

Other Virginia Beach residents killed in the public utilities office included Ryan Keith Cox, an account clerk for over 12 years; Joshua O. Hardy, an engineering technician for over four years; and Michelle "Missy" Langer, who worked as an administrative assistant for 12 years.

Herbert "Bert" Snelling, a contractor from Virginia Beach who was at the municipal building for a permit, was the only one among the 12 killed who was not an employee of the city.

Support is being provided to the families of victims as well as other city employees who were affected by the shooting, Hansen said.

The suspect, who was a longtime employee of the city, fired shots in every room of the building except for the basement, Virginia Beach police Chief James A. Cervera said at Saturday's news conference.

Cerver previously said that the shooter used a semi-automatic handgun and had multiple extended magazines. He also had a suppressor that muffles the sound of gunfire. On Saturday, Cerver said additional weapons were found at the scene and at the suspect's home.

The suspect was killed after being shot during what Cervera described as a "long-term gun battle" with police.

The motive behind the shooting is under investigation, he said.

Four people who were seriously injured in the attack continue remained hospitalized on Saturday morning. "A lot of us have said a lot of prayers that we are able to pull them through," Hansen said.

A police officer who was also injured is doing well, having been saved by wearing a bulletproof vest, according to Cervera.