(Image source from: NDTV.com)

An engineer for Virginia Beach’s municipal government, DeWayne Craddock, who indiscriminately shot at his colleagues reportedly informed his bosses in an email that he was resigning hours before he got into violent shooting.

Investigators, Craddock's former colleagues and residents of this stricken oceanside community on Sunday proceeded to grasp for hints to what caused the deadliest mass shooting in the United States since November.

Craddock killed 12 people before dying in a shootout with police.

According to city officials, what Craddock left was a resignation letter and a work history that provided no clue of his intentions.

A Virginia Beach city employee who witnessed a fatal shooting at a government edifice says he was face-to-face with the gunman during the rampage and shouted at him to stop.

"He merely submitted his two weeks' notice," said the person, who spoke on the condition of anonymity because the investigation is ongoing. "There was no foreshadowing of anything that resulted the rest of the day."

City Manager Dave Hansen said "a very thorough review" of Craddock's personnel file had revealed no problems. "To my knowledge, the perpetrator's performance was satisfactory," Hansen said, adding that Craddock "was in good standing within his department . . . there were no issues of discipline ongoing."

A public utilities account employee for the city, Christi Dewar who worked across the hall from Craddock, said she was aware of no incidents or arguments involving Craddock in the days before the shooting.

"There was absolutely no warning whatsoever," Dewar said.

Shortly before Craddock began Friday afternoon's massacre, he was in the office washroom, brushing his teeth, said city engineering technician Joseph Scott, who recalled exchanging pleasantries with him.

"Hi, how you doing? Any plans for the weekend?" Scott recalled saying. "That was pretty much it. Then we went our separate ways."

Officers received calls at about 4:00 p.m. about a shooter in Building 2 of the Virginia Beach Municipal Center.

Lacking a clear-cut idea of the shooter's whereabouts, officers entered that maze, in time encountering Craddock on the second floor. A protracted firefight turned up, and at 4:19 p.m. one officer was hit but was saved by his protective vest. Craddock, was at bay in an office and began firing through the door.

Police in the end broke down the door and started making an effort to save the life of Craddock, who was wounded. He was taken to a hospital and pronounced dead.

Between the time police were called to the incident and the time Craddock was subdued, 36 minutes had passed, according to officials.

Among the 12 people Craddock killed was the mother of a 22-month-old, a bagpipe enthusiast, civil servants, an immigrant from Belarus who assisted his friend with yard work - in what authorities described as an indiscriminate killing rampage.

The first victim of mass shooting was a contractor in the parking space. The second was a woman, who was her way out of the office.

Still an active employee at that time, Craddock was able to use his badge to gain entree to the building's second floor, where most of the killings took place.

In about an hour of the initial attack, all the injured had been taken to hospital.  In addition to those killed, four people were injured and hospitalized. All have undergone surgeries, officials said Sunday.

"They are progressing, and our prayers are with them," said Hansen, the city manager.

Authorities identified those killed as Virginia Beach residents Michelle "Missy" Langer, Ryan Keith Cox, Tara Welch Gallagher, Mary Louise Gayle, Alexander Mikhail Gusev, Katherine Nixon, Joshua Hardy and Herbert "Bert" Snelling; Chesapeake residents Laquita Brown and Robert "Bobby" Williams; Norfolk resident Richard Nettleton; and Powhatan resident Christopher Kelly Rapp.

The officials are still piecing together Craddock's whereabouts and timeline on Friday. It is still not distinct when and where he picked up the guns before the mass shooting began.

According to the Officials with the Bureau of Alcohol, Tobacco, Firearms and Explosives, Craddock's two pistols were legally bought in 2016 and 2018. An another legally purchased firearm was found at his home and a second gun that investigators were working to trace.

At the scene of the shooting, police recovered a sound suppressor.

At Sunday's news conference, city officials revealed that Craddock resigned Friday morning but did not share inside information of how or why he did so. "He notified his chain of command that morning," Hansen said. "My understanding is he did that via email."

Hundreds gathered Sunday morning near the iconic Neptune sculpture on Virginia Beach's sandy coast for an evangelical service hosted by Trinity Church.

Patty Richards said she had been praying since she heard that people had been shot at the municipal center not far from her house. Her husband, a contractor, had planned to go to that building on Friday for a permit but put it off until Monday.

Richards, a former critical cardiac nurse at a nearby hospital, said she understood too well what the medical professionals treating the victims would be facing.

"I know about that kind of pain," she said.

Cassandra Ellis, 47, stopped at the grocery store with her boyfriend for a dozen roses - one for each victim - adding them to the stack of flowers left in front of the Police Department.

"I go on my Facebook feed and that's all there is," Ellis said. "The vibes, the emotion is totally different. We're in a deep place, a bad place."

It was the deadliest shooting in the city's history, and the latest in the series of American gun massacres that now arrive with numbing frequency. The Virginia Beach shooting was the deadliest in the United States since a November shooting at a bar in Thousand Oaks, California, in which 13 people, including the gunman, were killed.

Robert Richardson, 39, a retired Navy veteran, said he had been drawn to the tightly knit community in Virginia Beach. "It has a big-city feel, but it doesn't act like a big city," he said.

On Sunday, Richardson brought his four children to see the flowers at the police station. "My kids go to school a block down the road," he said. "I fear for my kids when they go to school."

Richardson said he lived through the shooting at Fort Hood, Texas, in 2014 and never thought he'd see another workplace slaying like that one. Now that more have taken place, he can't say he's surprised.

"If we didn't learn from Sandy Hook, where all these innocent children died, we'll never learn," he said.

By Sowmya Sangam