A fatal shooting in an Orlando office building has added to the deadly toll of workplace violence in America this year.

Police were able to apprehend the alleged gunman, Jason Rodriguez, a former employee of the engineering firm where Friday's assault left one person dead and 5 injured.

Mr. Rodriguez had been fired by Reynolds Smith & Hills in mid-2007. The investigation into the incident and its possible motivations is ongoing. But after his Friday arrest, he responded to a reporter asking why he did it, saying "They left me to rot."

Ken Jacobson, a top manager and legal counsel at the engineering firm, told CNN that Rodriguez had been terminated after less than a year on the job, after failing to improve his work performance.

"His work was pretty deficient from the start," Mr. Jacobson said. He said the firm had not observed unusual personality traits.

The arrest followed several intense hours during which law enforcement officials from various agencies worked to ensure the safety of workers at the engineering firm and then track down Mr. Rodgriguez. He was found at his mother's home.

Workplace killings are not trending upward, according to annual statistics released by the US Labor Department. But the weak economy has boosted stress levels in many workplaces, and the Florida tragedy Friday came – coincidentally or not – only a day after widely publicized fatal shootings on the Fort Hood Army base in Texas.

"If you do have a high profile shooting, particularly like the one at Fort Hood that gets a lot of national attention, it may prod someone to act" who was already on the edge of violence, says Steve Kaufer, co-founder of the Workplace Violence Research Institute in Palm Springs, Calif.

The recession means more people are feeling financial or related anxieties, he says.

At the same time, employers have become increasingly focused in recent years on preventing workplace violence, and responding more effectively when it occurs. Those efforts have born fruit.

Overall, workplace homicides totaled 517 last year, despite the recession – the lowest in 16 years of tracking shown in a Labor Department report. That's half the rate seen in the early 1990s.

Most of the incidents, Kaufer says, don't involve co-workers or former employees. More typical is the convenience store robbery that turns violent.

But the risk is significant enough that employers across America have put in place training programs and other safeguards.

Much of it centers around communicating and acting on concerns.

If you see a big change in a colleague, or a lot of small changes, "it's probably a good idea to find out what's going on with that person," Kaufer says. Reporting concerns to a supervisor can lead to responses that typically don't lead to firing, but often help a troubled individual do better on the job.

Everything from badge-swipe access controls to threat-response policies have also helped to improve workplace safety.

Still, the Orlando shootings come on the heels of other high-profile instances of workplace violence this year.

The Fort Hood incident is a case in point, although it also has its own very distinctive circumstances – being at a military base, and with an alleged perpetrator disturbed about US war policies. The alleged killer of 13 people on Thursday, Maj. Nidal Malik Hasan, was an Army psychiatrist preparing for deployment to Afghanistan.

Another incident this year involved the murder of Annie Le, a researcher at Yale University, allegedly by a lab technician who worked with her.