Editor’s Note: The following story contains graphic details that some may find disturbing. Discretion is advised.

KNOXVILLE, Tenn. (WATE) — More charges have been brought against a Roane County couple accused in a child abuse case spanning Roane and Knox counties.

The defendants, Michael Gray Sr. and Shirley Gray each face murder and child abuse charges in Roane County and now, in Knox County after the remains of two of their non-biological children were found on their properties in Roane and Knox counties. The couple’s adult son, Michael Gray Jr. was arrested last week on first-degree murder charges.

Michael Gray Sr. and Shirley Gray have both pleaded not guilty to all the Roane County charges.

Back in May, the remains of a girl, one of the couple’s non-biological children, was found on the property of Michael Gray Sr. and Shirley Gray in Roane County.

Just days later, remains of another child were discovered buried at a Knox County home previously occupied by the Grays.

Michael Gray Jr. and Shirley Gray will be arraigned on Thursday.  Michael Gray Sr. will be arraigned on Friday; all of these arraignments will be in Knox County Criminal Court – Division 3.