A few high-profile incidents have increased awareness about on-the-job violence.
- Last year, a disgruntled 55-year-old civil servant in Kamloops, B.C., shot and killed his boss and a co-worker and then committed suicide after he received a letter of discipline.
- In 1999, a former employee of OC Transpo killed four workers and then himself at a bus maintenance garage in Ottawa. An inquest found he had been harassed and bullied on the job.
"When these things happen, everyone jumps to it and says, 'My goodness, are we becoming violent?'" said French. "Well, we've been violent all along. We just haven't shown it in a physical act, but that may happen."
Hy Bloom, a forensic psychiatrist and workplace violence consultant, said on-the-job aggression has many roots, including downsizing, competition and the resulting stress on workers; a predisposition to aggression in individual employees, including a history of violence, substance abuse or attitudinal problems; and the absence of workplace policies that address harassment and violence.
"I'm not sure a guy hell-bent on coming back to the workplace with guns ablazing is going to be deterred by a policy, but ... there's a spectrum here that may include bullying, harassing, threatening, mild aggression, intimidation - those kinds of people may well be deterred by the spelled-out consequences," said Bloom.
Companies should encourage employees to disclose confidentially changes in disposition or threatening behaviour among co-workers.
But sometimes the source of aggression and violence in the workplace isn't an employee or supervisor, but a client or customer. Health-care and retail workers are at particular risk, statistics show.
Domestic disputes can also be imported into the workplace.
"It has healthy representation," said Bloom. "What happens here is husband or jilted consort knows the most likely place he can find the spouse that has just left him and is now incommunicado ... is work. She's not likely to give up her job. So he goes there and often there's an associated idea that not only will he find her there, but he may well find some interfering male that has become an object of her interest and distanced the two of them."
In the heat of the moment, co-workers who intervene can become targets. In 2000, the manager of a Starbucks coffee shop in Vancouver was fatally stabbed after he stepped between an assailant wielding a knife and a female employee. The employee's estranged husband was charged with second-degree murder.
"One's personal life has always been something that's seen as separate from work, so you don't report it to your workplace," said French. But employers should encourage workers who fear a domestic dispute could spill into the workplace to report their concerns so the company can takes steps to protect them, he said.
Ottawa and some provinces have enacted "a dog's breakfast" of legislation that places varying burdens on employers to protect workers from on-the-job violence, French said. And employers are paying more attention to anti-violence policies, security, how they fire people and signs of emotional problems among employees.
In the end, however, many workplaces leave workers hanging.
"If a fire alarm went off, most of us would know what to do. It's posted everywhere," said French.
"However, if someone were to become highly aggressive and lethal in the workplace, very few of us know what to do."