The problems were flagrant, and his boss began to document them, only months after Vester Lee Flanagan II started working as a reporter at television station WDBJ in Roanoke, Va.
He had a "heated confrontation" with another reporter inside a station truck, according to a memo by the news director. He ripped into a cameraman because he did not like the way he was filming, and colleagues said he made them feel "threatened or uncomfortable." Flanagan was ordered to obtain counseling from employee assistance or lose his job. He complied, but because of his continuing belligerence and other performance issues he was fired anyway, less than one year into the job.
Flanagan stormed out of the news director's office when told he was being dismissed and slammed a door so hard that nearby workers hid in a locked room. Station officials called the Roanoke police, who came to escort him out, but not before he handed the news director a small wooden cross and said, "You'll need this."
The station hired off-duty police officers to guard the building for the next two days and hoped that the problems with Flanagan were over.
But they were not: More than two years after being fired, Flanagan shot to death Alison Parker, a young reporter, and Adam Ward, a cameraman he had once worked with, while they were on the air Wednesday on assignment.
It is a nightmare for any employer: what to do with a volatile, constantly aggrieved worker who has had angry, even frightening confrontations with fellow workers — yet has committed no crime. Because he had no convictions or been adjudicated mentally ill, Flanagan was able to legally purchase from a licensed dealer the Glock 19 handgun used in the killings after passing a background check in June, federal officials said.
At a news conference Thursday, the station manager of WDBJ was asked if there was anything more the station could have done to protect its workers.
"We can probably screen more," the manager, Jeff Marks, said, though he went on to speak about how difficult it is to get an honest reference from a former employer.
Employers face conflicting legal obligations and huge uncertainties. They have a legal duty to provide a safe workplace, and can even be sued for failing to prevent predictable threats, according to legal experts.
On the other hand, they must tread carefully with employees who may have mental health problems. The federal disabilities act prohibits discrimination against disabled people, including those with mental illness.
For every angry employee who might pose a serious threat, there are far more who will not and whose privacy and rights must be respected. And there is no surefire screening method.
"It's nuance," said Linda Doyle, an expert in employment law with McDermott Will & Emery in Chicago.
"Not every one of these is a Mr. Flanagan," she said, referring to people whose behavior seems problematic. "The goal is to help the person be well and change the behavior, but the other goal is to protect your workplace."
Federal law since the 1970s has made it clear that employers are responsible for providing work sites that are free of hazards, which government rules and court decisions have established can include workplace violence, said Corinne Peek-Asa, associate dean for research in the College of Public Health at the University of Iowa and director of the university's Injury Prevention Research Center.
"If you can convince a jury that a business should have seen it coming, and should have done something about it, more often those cases are going against the employer, especially jury decisions," Peek-Asa said.
Many larger companies have devised systematic approaches to prevent workplace violence, "but there are huge gaps in the programs of many middle- and small-sized businesses," she said.
Dealing with employees whose anger and aggression may be tied to psychiatric disorders poses special challenges. Under the Americans With Disabilities Act, employers must accommodate workers who have mental health issues as long as they are able to do their job, and employers can be sued for revealing medical information to a third party, said Joseph A. Seiner, an expert on employment issues and a professor at the University of South Carolina School of Law.
Still, "employers do not have to tolerate acts of violence," said Elizabeth Bille, vice president and associate general counsel at the Society for Human Resource Management. "Even if a behavior such as a threat of violence is the result of a mental health condition," she said, employees can be terminated.
Still, some people may continue to nurture their grievances no matter how their firing was handled.
"You can try to know as much as you can about the person before they depart," said Stephen G. White, a psychologist and president of the consulting firm Work Trauma Services Inc. Employers can have precautionary measures in place when it seems appropriate, such as legal protective orders. But in the end, he said, comes a very difficult judgment call.
"You're looking for that needle in the haystack," White said. "You don't want to miss a hot one, but you don't want to overreact to situations that are low risk."