KNOXVILLE, Tenn. (WATE) — The adult son of an East Tennessee couple charged in the deaths of two of their children has now been arrested.

Michael Gray Jr. was arrested and booked into the Knox County Jail early Thursday morning on charges of attempted first-degree murder; however, later in the day those charges were amended to first-degree murder.

Michael Anthony Gray, 63, and Shirley Ann Gray, 60

His parents, Michael Gray Sr. and Shirley Gray both face murder and child abuse charges after the remains of two of their non-biological children were found at their properties in Roane and Knox counties.

Their son had lived at the Knox County property in Halls. He had told investigators that his parents didn’t tell him one of the kids died and was buried on the property.

Instead, he said his parents claimed that the Department of Child Services took all the children away except for one.

Gray Jr. is being held on $500,000 dollars bond.

We’ll continue to follow this story and bring you an updates as we get them.