When Timothy Jones Sr. learned his grandchildren were missing, a deep, unshakable dread set in, and he feared his own son had killed them.

“I remember I told my wife, ‘I know he’s killed them,’” the patriarch tearfully recalled to Fox News Digital. “I just don’t know where they are. But I know he has. I just know it in my heart. I could feel it.”

Timothy Jones Jr. admitted to killing his five children, ages 1 to 8, in their Lexington County, South Carolina, home in August 2014.

He drove with their bodies in his SUV for nine days before dumping them in five garbage bags on a hillside near Camden, Alabama.

Jones Jr.…