Gary Montez Martin, the man who opened fire inside a manufacturing company in Aurora, Illinois, legally should not have been in possession of a firearm, police said on Saturday.
On Friday, Martin, who had been an employee of the Henry Pratt Co. for 15 years, opened fire at a meeting during which he was being terminated from his job, according to Aurora Police Chief Kristen Ziman.
Ziman said that Martin shot at the person who was firing him and others in the meeting before moving outside the room.
"We believe that several people who were involved in that meeting are the ones who are deceased," Ziman said during a press conference on Saturday.
Martin killed five people in total and injured several police officers during the rampage on Friday afternoon, before being shot and killed by police.
During the press conference, Ziman named the victims, who were all employees of Henry Pratt Co.: Clayton Parks, the human resources manager; Trevor Wehner, a human resources intern and a student at Northern Illinois University; Russell Beyer, a mold operator; Vicente Juarez, a stock room attendant and forklift operator; and Josh Pinkard, the plant manager.
Another unidentified victim was treated at a nearby hospital for non-life-threatening gunshot wounds.
The injuries the police officers sustained during the shooting are all considered non-life-threatening.
On Saturday, Ziman said that Martin, 45, purchased a handgun on March 6, 2014, after being issued an Illinois Firearm Owner’s Identification (FOID) Card in January of that year. The firearm, a Smith & Wesson .40 caliber, was in Martin's possession as of March 11, 2014.
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The FOID card application process includes a background check, but applicants are not fingerprinted, Ziman said.
It was only when Martin applied for a concealed carry permit on March 16, 2014, that he was fingerprinted and it was revealed he had a 1995 felony conviction for aggravated assault in Mississippi.
Ziman said that upon the discovery of this conviction, Martin's concealed carry permit was rejected and his FOID card was revoked.
"Absolutely he was not supposed to be in possession of a firearm," Ziman said.
Ziman said that, after officials discovered Martin's felony, a letter was sent notifying him that his FOID card had been revoked and informing him that he was required to relinquish his firearm to local authorities. She added that law enforcement is now investigating if they ever followed up with Martin.
Martin also had six prior arrests with the Aurora Police Department, including arrests for traffic and domestic violence-related issues, according to Ziman. She said his last arrest in Aurora was in 2008 for violating an order of protection.
However, Ziman said Martin was last arrested in 2017 by the Oswego Police Department for disorderly conduct and criminal damage to property.
Scott Hall, president and CEO of Mueller Water Products, the parent company of Henry Pratt, said that Martin was being fired "for a culmination of various workplace rules violations." He added that a background check was done when Martin was hired 15 years ago and that did not turn up the Mississippi felony conviction.
Martin was killed by police after a "very short gunfight" with officers, Aurora police Lt. Rick Robertson said.
"There was the initial contact with the officers and then after those shots everything went quiet" and officers began entering the building to search for him in the large facility, he said. It appears that Martin retreated into the facility and was waiting for police, Robertson said.
"He was in a back machine shop at the very back corner of the building, farthest from the area that we made entry into the building," Robertson said. "He was probably waiting for us to get to him there, is the way that it appeared, and there were some shots exchanged as the officers made their way into that area."
"He was basically in the back waiting for us and fired upon us" and officers fired back, he said.
Hall said their thoughts are with the families of the victims and the employee who was shot and wounded, and thanked first responders.
"We will be reviewing every aspect of this tragedy and the steps we need to ensure this horrible incident is never repeated," he said. "We are assessing if there is anything we could have done or could do in the future."
The employee who was wounded was expected to be released from the hospital Saturday, Hall said.
Ziman said she is not sure that Martin was aware that he was going to be fired, but "We can surmise that he was speculative about what was going to happen, as evidenced by him arming himself with a firearm — that’s again, we're speculating there."
Multiple spent magazines were found, she said. There was a laser on the gun.
The wounded officers are all expected to survive, Ziman said, but in addition to the physical pain there is emotional pain as well. She said the families of the victims are foremost in the department’s thoughts.
"I know that with the lives lost, the officers are wishing they could have done more," she said.
Kalhan Rosenblatt is a reporter for NBC News, based in New York.