aurora police chief
Aurora police chief: Those who died did not deserve this
02:08 - Source: WGN
CNN  — 

Gary Martin took a gun into work Friday, a pistol he didn’t legally own.

The work day began as usual at 7 a.m. CT. That afternoon Martin was called to an office at Henry Pratt Co., a manufacturing business in Aurora, Illinois, a large suburb 40 miles west of Chicago.

While it is unknown whether Martin knew he was about to be fired, a company official said he had been going though a discipline procedure and he had been written up before.

After the termination meeting, Martin took out his pistol and began killing people, witnesses told police. He left the meeting room and kept firing as he went into the warehouse, where there were only a handful of employees.

All told, he gunned down a plant manager, a human resources manager, an intern on his first day, and two other workers. He wounded one other colleague.

He also shot at responding police, wounding five, before going into hiding in the back of the facility.

Martin, 45, died in a shootout after officers painstakingly went through the 29,000 square-foot warehouse.

Now police are trying to figure out why Martin still had his Smith & Wesson .40 caliber pistol. And the company where America’s latest mass shooting took place is trying to figure out what it could have done to prevent the tragedy.

Martin was a felon

Martin had a 1995 felony conviction in another state, Aurora Chief of Police Kristen Ziman said Saturday.

Gary Martin is seen in this image taken from Facebook.

Martin’s conviction was flagged only days after he bought a handgun in 2014, and he was supposed to relinquish it, she said.

That pistol – and a laser sight – was used in Friday’s shooting, and now investigators are trying to find out why he still had it, she said.

“He was not supposed to be in possession of a firearm,” Ziman said.

The slain men included a plant manager and a college student

Police on Saturday released the names of the five workers killed at the industrial valve manufacturer’s 29,000-square-foot warehouse:

• Clayton Parks of Elgin, Illinois, a human resources manager.

• Trevor Wehner of DeKalb, Illinois, a human resources intern and a student at Northern Illinois University.

• Russell Beyer of Yorkville, Illinois, a mold operator.

• Vicente Juarez of Oswego, Illinois, a stock room attendant and fork lift operator.

• Josh Pinkard of Oswego, Illinois, a plant manager.

The names of five wounded police officers and the wounded worker – all men – were not immediately released. Of the wounded officers, four were shot and one had shrapnel wounds, police said.

At least three of the officers still were being treated at a hospital Saturday morning, police said. None of the injuries was believed to be life-threatening.

Law enforcement officers gather outside the Henry Pratt Co. manufacturing plant in Aurora, Ill.