NORFOLK, Va. -- A city engineer who fatally shot 12 people in a Virginia Beach municipal building in 2019 "was motivated by perceived workplace grievances" that "he fixated on for years," according to findings released by the FBI on Wednesday.
The investigation, conducted by the FBI's Behavioral Analysis Unit, found that 40-year-old DeWayne Craddock "struggled with how he perceived his own work performance and how others at work viewed him."
"The shooter's inflated sense of self-importance contributed to this conflict and led him to believe he was unjustly and repeatedly criticized and slighted," the FBI said in a news release. "Violence was viewed by the shooter as a way to reconcile this conflict and restore his perverted view of justice."
But the FBI cautioned that no person or group was in a position to "see the confluence of behaviors that may have forewarned the attack" because Craddock had purposely isolated himself and disengaged from his relationships.
The agency also said that Craddock suffered from significant mental health stressors, although they "alone cannot explain the Virginia Beach attack."
"It is important to note that only the shooter knew the real reason why he committed this horrific act of violence; however, at this time, the FBI is confident, based on evidence collected, that the above assessment is accurate," the FBI stated.
The FBI's findings appear to go a step further than two previous investigations into the mass shooting.
Virginia Beach police said in March that they could not determine a motive.
"Despite exhaustive investigative work and in spite of unsubstantiated rumors and accusations, it appears we may never know why he committed this heinous act," the city's report concluded.
Craddock had worked in the city's public utilities department for more than nine years. He killed 11 co-workers and a contractor who was in the building at the time getting a permit. Four others were seriously wounded and a police officer responding to the shooting received a bullet in his tactical vest but escaped serious injury. Craddock was killed in a shootout with police.
The city's report had said Craddock's life began to change around 2017. He was getting a divorce and started to have performance problems at work. In 2018, he received a written reprimand for poor performance, failed to meet expectations on an evaluation and didn't get a merit raise.
"At times, the suspect referenced the belief he was being tasked with work outside of his pay grade," the city's report said. "This concern was specifically addressed by his supervisor in 2018. The suspect was told that he had been making improvements and was given encouragement."
Leaders in the department said the shooter would have met job performance standards in his 2019 evaluation, the report said.
The city's report said investigators didn't uncover "any indications of violent tendencies or acts of violence committed by the suspect prior to May 31, 2019."
It echoed similar findings released by Chicago-based security company Hillard Heintze in November 2019. The firm offered no clear motive and said that Craddock "did not work in a systemically toxic workplace."
The FBI's report, however, is somewhat validating for some of the victims' families who have long blamed what they say was a toxic workplace environment and a failure by supervisors to recognize warning signs.
Jason Nixon, whose wife, Kate Nixon, was killed, has long said that the shooter was upset because he was having trouble at work and lost out on a promotion.
"Human resources dropped the ball on policies, protocol and procedures," Nixon said in March. "My wife warned them all the time that there's something wrong with this guy."
Nixon said Wednesday that he expects little to come of the FBI's report because Virginia Beach "plays by its own rules."