PONTIAC, Ill. (AP) — A suspended state corrections officer pleaded not guilty Thursday in the Christmas Day shootings of his wife, adult son and another man in a small eastern Illinois community.

Clifford Brewer, 53, of Cullom is charged with six counts of first-degree murder and remains in custody in lieu of $500,000 bond. He is accused of shooting his wife, Shirley, 48; his son, Christian, 27; and neighbor Norman Walker, 51. They were all found in Brewer’s home with single gunshot wounds to their heads.

Livingston County State’s Attorney Randy Yedinak would not say whether a motive for the shootings has been determined, The Pantagraph reported.

“We’re confident in the charges and we’re confident in our case,” Yedinak said after Thursday’s court hearing.

Brewer’s attorney, Joshua Richards, declined to comment.

Yedinak has said Brewer went birthday shopping for his wife, but the two argued when he returned home on the evening of Dec. 24.

Walker was invited to the house by Shirley Brewer, and the two drank and played loud music in an upstairs bedroom, court documents say. Brewer told police he fell asleep and a few hours later, discovered the bodies and a gun near his wife’s body.

Brewer is an officer with the Illinois Department of Corrections who has been placed on administrative leave.

If convicted, Brewer could face life in prison.