Shanann Watts' family opened up Monday about the five-hour confession tape of her killer Chris Watts, saying how they struggled with the deaths and with understanding why her husband committed the murders.

Shanann's brother, Frank Rzucek Jr., said the family didn't think Chris had killed his wife "until we saw that interview" on television, CNN reported.

Recently, authorities released Watts' interview, which was recorded in February. Watts opened up about his state of mind in the weeks and months leading up to his conviction. He also gave details about the murder and what led him to plead guilty. 

Chris killed his pregnant wife and two young daughters after an argument with his spouse on Aug. 13, 2018. He had told his wife he was having an affair and wanted a divorce.

On Monday, Shanann's mother appeared on the "Dr. Phil" show where she said she knew something terrible had happened to her daughter, even before the Colorado mother was reported missing.

Sandy Rzucek recalled something woke her from her sleep last year, and she sat up in bed. "I heard the Holy Spirit say, 'Shanann,'" she said. 

"I felt my daughter's spirit the moment she died," she said during the appearance. "I knew. I swear to God I knew. ... I woke up the whole house. I said, 'Something's wrong with Shanann.'"

The bodies of Shanann and her children, Bella, 4, and Celeste, 3, were found in August in a secluded oil field where Chris worked. In November, Chris pleaded guilty to the killings, and was serving five life sentences -- three consecutive and two concurrent.

Watts had initially denied involvement in the disappearance of his wife and children, and expressed concern about their well-being.

"Why do you think he's telling the truth now?" asked host Phil McGraw to Shanann's brother on Monday.

Frank said he believed Watts spoke honestly about the killings because "I think it's eating him up." 

"I think he was more than glad to talk to somebody for five hours, sitting in a box 24/7," said Rzucek, who was the children's godfather.

In an appearance recently on "Dr. Phil," a lawyer for Watts' family said Chris' 4-year-old daughter walked in on her father as he was strangling his wife. After killing his wife, Chris smothered his two daughters.

“From our understanding, Bella did not witness the actual killing of her mother, Shan’ann,” the legal representative told Dr. Phil. “It was not until Chris was in the process of trying to dispose of Shan’ann’s body, essentially wrapping her up in this sheet.”