D.C. Police say two men are facing second-degree murder charges in the slayings of their fathers in separate cases.

Media outlets report an arrest affidavit says 71-year-old Dr. Harrison Spencer was found dead from multiple stab wounds in his home Wednesday evening. Thirty-two-year-old Peter Michael Spencer called 911 saying he had killed his father after "voices" in his head told him to do it.

The Tulane University website says Harrison Spencer was a doctor who spent much of his career working for the Centers for Disease Control and Prevention. He also was a dean at Tulane.

Peter Spencer's attorney, David Maxted, declined to comment.

Wednesday afternoon, 44-year-old Otis Byrd was stabbed to death outside Children's National Medical Center.

Byrd's son, 20-year-old Brandon Byrd, was arrested in the death. It's not clear whether he has an attorney.