OKLAHOMA CITY - Investigators are working to determine a motive behind the terrifying Thursday night shooting at Louie’s Grill and Bar at Lake Hefner. Police believe the shooting and location was random.

Oklahoma City Police Department’s Captain Bo Mathews addressed media the day after shooting. Police identified Alexander Tilghman, 28, as the shooter. He is now deceased.

“It looks like his mind was made up that he was going to discharge his firearm once he got there,” said Capt. Bo Mathews, Oklahoma City Police Department.

Mathews said Tilghman was armed with a handgun and wearing protective gear coverings when he drove to the restaurant. He fired at the front door of the restaurant, hitting and injuring three patrons inside. Two citizens outside were close enough to jump in to help.

“The firearms were in the trunk of their vehicles,” said Mathews. “When they saw this incident breaking out they were able to go to their vehicles and gather their firearms.”

The two men shot Tilghman dead only feet from the restaurant.

Now detectives turn their investigation to the gunman's home, history and what he was doing prior to the shooting.

“They did go to his, I believe he may have an apartment,” said Mathews. “They searched it. What they found at this point I do not know.”

The shooter's personal videos and social media posts will also be part of the investigation.

“We have our homicide and criminal intelligence investigators looking into this,” said Mathews. “So that is some of the research and some of the things they will be looking into so we can find what led up to this incident.”

Police do not have an adult arrest record on Tilghman, only a juvenile incident from 2003. Police said it was an assault and battery case involving his mother.