OKLAHOMA CITY (AP) - A doctor from suburban Oklahoma City has been charged with first-degree murder in his 9-year-old son's stabbing death.

Oklahoma County prosecutors also charged Stephen P. Wolf with assault and battery with a deadly weapon Wednesday for an assault on his wife, Mary, during the same Nov. 16 incident.

A probable cause affidavit shows that a police officer answering a call of a suspicious person heard Mary Wolf screaming that someone was killing her son, Thomas.

According to the affidavit, Officer Michael Puckett found Stephen Wolf on his knees wrestling with something in the kitchen of the family's Nichols Hills home. Puckett says he ordered Wolf to put his hands up and that Wolf told him, ``You know he's got the devil in him.''

Medical records indicate Stephen Wolf has a history mental problems.

Wolf's attorney couldn't be reached to comment Wednesday.