(CNN) — The gunman, Gary Martin, 45, shot several of the men at a meeting during which he was being fired, Aurora Police Chief Kristen Ziman said Saturday. At least one of the slain men was found on another level in the building, she said.
Martin was not supposed to own a gun because of a 1995 aggravated assault conviction in Mississippi, she said.
But he obtained one in Illinois in 2014. In January of that year, he applied for a firearms owner identification card, she said.
In March 2014, he applied to buy a gun from a dealer in Aurora. After a waiting period and passing a background check that did not involve fingerprinting, he bought the gun, she said.
Later that month, he applied for a concealed carry permit, and a fingerprint check led authorities to discover the Mississippi conviction, Ziman said.
The permit was rejected, and Illinois State Police sent him a letter demanding he voluntarily surrender the weapon, but he did not, the chief said. Investigators are trying to determine why he didn’t surrender the weapon and whether law enforcement followed up with him to confiscate the gun.
“He was not supposed to be in possession of a firearm,” Ziman said.