Update: The Associated Press confirms that the identity of the shooter is 36-year-old Andrew J. Engeldinger. Police say he had 10,000 rounds of ammo in his his home and he had been fired hours before the shooting.

Authorities say a gunman killed at least four people and then took his own life at a sign plant in Minneapolis on Thursday night.

The family of Accent Signage Systems Inc. founder Reuven Rahamim said he died in the attack. Other employees of the sign company and a UPS truck driver were also reportedly killed, according to KARE.

Employees of the company told KARE that the shooter had been fired earlier in the day.

"It's insane. It's crazy," Heather Buckingham, who lives nearby, said. "I know the guy, I know all the people. .... The one that was doing the shooting was quiet; kept to himself."

Several employees identified the suspect as 36-year-old John Andrew Engeldinger. Although police searched a home at the address listed on Engeldinger's voter registration, they had not confirmed that he was the shooter by Friday morning.

Neighbors said that the occupant of the home had been arrested by police a week earlier and had kicked out a squad car window.

Watch this video from KARE, broadcast Sept. 28, 2012.