Updated

Narcotics investigators have seized medical records from the office of a former Oklahoma City-based doctor who faces possible murder charges after eight patients died of prescription drug overdoses and another allegedly caused a fatal traffic accident.

An affidavit for a search warrant filed Monday says the records were seized from the office of 71-year-old William Martin Valuck. Federal agents arrested Valuck Friday at his home in Kilgore, Texas.

The search warrant affidavit says state and federal agents seized the medical records on Thursday. The document says agents took patient charts for seven patients and Valuck's office staff surrendered the charts of three other patients.

An arrest warrant affidavit says Valuck surrendered his medical license on Dec. 13.

Valuck's attorney didn't immediately respond to a phone message Monday.