SPRINGFIELD, Mo. (AP) — Greene County Sheriff Jim Arnott says the deaths of two people last weekend in Springfield were a murder-suicide.

Arnott said 66-year-old Robert O'Block and his 27-year-old girlfriend Tiffany Fleming died from single gunshot wounds. The sheriff says the investigation indicates that O'Block murdered Fleming before shooting himself. Their bodies were found Sunday.

Arnott says the investigation will continue and toxicology results are still pending.

O'Block was the CEO of the Center for National Threat Assessment. It is the parent company of American College of Forensic Examiners International and other groups that certify people in fields such as homeland security, forensics, psychotherapy and integrative medicine.

Springfield police are investigating a burglary that occurred at the business earlier this week.