The gunman who prompted a campus lockdown at Arkansas State University said he initially wanted to shoot other people but changed his mind and was planning on killing himself before he was arrested, police said Friday.

Brad Kenneth Bartelt was held Friday on a preliminary charge of aggravated assault for the Thursday incident, in which students and staff were ordered to evacuate the student union. Jonesboro police spokesman Paul Holmes said additional charges are likely.

Bartelt will appear via video link from the Craighead County jail before a judge, who will consider whether there was probable cause for his arrest and whether bond should be set. Holmes said he did not know whether Bartelt had an attorney.

Bartelt, 47, of Jonesboro, had a 12-gauge shotgun and containers of gasoline and propane with him when he drove his truck onto a plaza east of the student union, Jonesboro Police Chief Rick Elliott said.

Bartelt called 911 after driving onto the plaza and told dispatchers he was on campus with a gun, police said in a report released Friday. While talking with negotiators, he waved his gun and threatened to shoot the propane tank, the report said.

After he was taken into custody, Bartelt told police he was upset over an injury he received while training to drive an 18-wheeler at Arkansas State's Newport campus, 45 miles away.

"He said they did not treat him right and pay for certain expenses and bills resulting from the injury," the report said. "He stated that he was going to come to the university and shoot other people but he realized that murder would be wrong, so he was going kill himself."

In a Facebook post Wednesday, Bartelt said he was feeling homicidal and suicidal and complained about a recent decision in a Social Security case, police said.

Bartelt was injured when his driving partner ran over him when he was retrieving a 50-pound barrel, according to a filing with the state worker's compensation commission.

Elliott said at a Thursday news conference that Bartelt never pointed a weapon toward officers.

"He was pointing the gun at himself. He wanted to do harm to himself," Elliott said.

The chief said that, when he arrived, Bartelt was sitting in the truck with his foot out the window and the shotgun visible, yelling something inaudible. He said from "time-to-time" Bartelt would get out of the truck and slosh gasoline on the truck or hold the shotgun to his chin. Bartelt eventually threw the shotgun down and surrendered, Elliott said.

Bartelt told police he was on several psychiatric medications and painkillers, according to the report released Friday. Police said they found an AR-15 during a search of Bartelt's home after his arrest.

"He also stated that he was seeing demons in the woods around his house and had tried to photograph them, but was not able to get their pictures," the report said.