(CNN) -- As Virginia Beach mourns 12 people gunned down in a shooting rampage, more questions remain on why a veteran city engineer targeted people he'd worked with for years.
The gunman fired indiscriminately Friday on a municipal building in the coastal city in Virginia before he died after a long shootout with police officers.
As officials struggle for answers, Mayor Bobby Dyer has tried to quell both sides of the gun control debate, saying he wanted to avoid the "knee jerk reaction" and the "bipartisan bureaucratic malpractice."
"There's a lack of civility. There's a lack of mutual respect. There's a lack of willingness to understand each other," Dyer said Saturday.
Here is what we know so far -- and what we don't.
The mass shooting and the target
What we know: The shooter was a "disgruntled employee" in the municipal building he attacked, a Virginia government source said.
On Friday toward the end of the work day, he shot one person in a car and then entered the building where he fired at people on three floors.
What we don't: Authorities are still searching for a motive, and those who knew him say they didn't see the horror coming.
"I guess the big question is, why? We want to know, too," Dyer said.
Joseph Scott said he worked with the shooter for several years and saw him that day. He said the suspect was brushing his teeth in the bathroom, as he always did, and wished him a good day. He was "what I thought was a good person," Scott said of the shooter.
The victims and their conditions
What we know: Twelve people were killed in the attack and several others were wounded, with three people in critical condition and one in fair, hospital officials said Saturday.
Those killed include Herbert "Bert" Snelling, who was trying to file a permit when the gunman opened fire.
Three right-of-way agents were killed: Laquita C. Brown, with four and a half years years in the public works department; Mary Louise Gayle, with 24 years in the department; and Alexander Mikhail Gusev, with nine years in the department.
Also slain were engineers Tara Welch Gallagher, who spent six years in the city's public works department; Katherine A. Nixon, who worked in public utilities for 10 years; Richard H. Nettleton, who worked for the city's public utilities department for 28 years; and Christopher Kelly Rapp, who had been in public works for 11 months.
Joshua O. Hardy, an engineering technician for four and a half years in the public utilities department was also killed, as was Ryan Keith Cox, an account clerk, who had spent 12½ years in the public utilities department.
Also killed in the attack were Michelle "Missy" Langer, an administrative assistant who worked 12 years in public utilities, and Robert "Bobby" Williams, a 41-year veteran in the public utilities department and special projects coordinator.
What we don't know: Why their workplace was targeted.
What we know: 40 members of law enforcement, mostly FBI, were at Building 2 to collect evidence.
They found two legally purchased .45-caliber pistols at the scene -- one the shooter bought in 2016 and one in 2018.
Police said one pistol had a suppressor and several empty extended magazines. And Investigators found even more weapons in the gunman's home, Chief James Cervera said.
What we don't: Questions remain about why he purchased the weapons and how long he was planning his attack.
The gunman and his family
What we know: The gunman was identified as 40-year-old DeWayne Craddock, who worked as a certified professional engineer in the city's public utilities department for 15 years.
His neighbor, Clarisa Morel, said the gunman had three security cameras set up in two of his windows and once catcalled her.
Another neighbor, Cassetty Howerin, said he was awake all hours of the night, but mostly kept to himself.
What we don't: We don't know if the gunman had previously threatened anyone in the building or had conduct issues at work; Cervera declined to answer questions about that Saturday.
The shooter's parents, reached Friday night, told CNN they weren't aware of any trouble that he was having with his employer. The family posted a handwritten message on their front door but focused on the victims rather than the perpetrator.
"We are grieving the loss of our loved one. At this time we wish to focus on the victims and the lives (lost) during yesterday's tragic event," they wrote. "Our thoughts and prayers are with the families of those who (lost) their lives, and those recovering in the hospital. -- The Craddocks."
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