— -- The parents of a Kentucky woman last seen 10 days ago suspect foul play in her disappearance.
Crystal Rogers, 35, a mother of five, was last seen by her live-in boyfriend, Brooks Houck, on July 3, according to the Nelson County Sheriff’s Office.
Houck has said he had nothing to with Rogers’ disappearance. He has been extremely cooperative with investigators, police said, and he took a polygraph test.
"I'm 100 percent, completely innocent in this,” he told HLN’s Nancy Grace, adding that his search efforts have been done "behind the scenes."
”I want the emphasis to remain on Crystal’s safe return," Houck said.
But Rogers’ parents, Tommy and Sherry Ballard, told ABC News in an interview that they’re not convinced by Houck’s story.
“He's had no emotion. it’s like nothing has changed for him. And to us, our whole world has changed,” Sherry Ballard said.
The family was involved with weekend search efforts.
“All the support from the community just means the world to us,” Sherry Ballard said.
Rogers’ car, a maroon Chevrolet, was found with a flat tire alongside Bluegrass Parkway. But her relatives said Rogers rarely visited the area where the car was found. Her keys, purse and uncharged cell phone were found inside.
“I know she wasn’t in that car,” said her father, Tommy Ballard.
Investigators haven't named Houck or anyone else as either a suspect or person of interest. A $71,000 reward is being offered for Rogers' return.