Five people were tragically murdered when a man opened fire on Friday inside a manufacturing warehouse in Aurora, Illinois.

Almost immediately after news of the mass shooting spread, Democrats and gun control advocates — before many of the basic details were reported, yet alone known — used the tragedy to bolster the gun control narrative.

Unfortunately for gun control advocates, Illinois law enforcement released a key detail Saturday busting the narrative that more gun control may have prevented Friday's tragedy.

What did police say?

According to law enforcement, the killer was a convicted felon. That means he was already ineligible to purchase or possess a firearm.

"He absolutely was not supposed to be in possession of a firearm," Aurora Police Chief Kristen Ziman said Saturday, according to NBC News.

Ziman explained at a news conference that the killer purchased a .40 caliber Smith & Wesson handgun on March 6, 2014 after being issued an Illinois Firearm Owner's Identification Card, or FOID.

Unfortunately, FOID applications only require a background check, and not mandatory fingerprinting. That means the shooter's 1995 felony conviction for aggravated assault in Mississippi did not surface until he applied for an Illinois concealed carry permit on March 16, 2014.

It was only when the killer's previous felony conviction surfaced that Illinois authorities denied his concealed carry application and revoked his FOID.

More from NBC News:

Ziman said that, after officials discovered [the killer's] felony, a letter was sent notifying him that his FOID card had been revoked and informing him that he was required to relinquish his firearm to local authorities.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 [the killer].



[The killer] 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 [the killer] was last arrested in 2017 by the Oswego Police Department for disorderly conduct and criminal damage to property.

In addition to the five employees tragically murdered, five Aurora police officers were shot during a shootout with the killer; a sixth was injured while responding to the incident, according to WLS-TV. All officers are expected to make full recoveries.

What did Dems say?