Gabby Petito's father has slammed Brian Laundrie and his family as "cowards" in a new interview with Dr. Phil.
Heartbroken Joseph Petito revealed he doesn't think Laundrie has killed himself as he lacked the courage to do so.
"Anyone who lived in that house is a coward," Petito said, referring to the home in North Port, Florida, where Brian's parents Christopher and Roberta live.
"They don't know how to stand up for their actions."
Gabby's dad and stepmother Tara Petito were joined by Gabby's mother Nichole Schmidt and stepfather Jim Schmidt, as they all sat down for their first joint interview with Dr. Phil.
Watch Gabby Petito's family speak to Dr. Phil:
Joseph again called on Laundrie's parents to come forward with what they know.
The family spoke about the excruciating days they spent trying to contact the Laundrie family for news of their daughter after she stopped communicating with them in late August.
Gabby's mom Nicole said it was "infuriating" that her text messages and calls to Laundrie and his mother Roberta were ignored.
"We actually thought that they were both missing at that time," Joseph said.
In one of the text messages, Joseph told the Laundries: "I'm going to call the police, just letting you know, because we have no idea.
"A normal parent when you text someone that (you) are going to call the cops because you can’t find your child, they would reply. No response. Nothing," he added.
He then questioned what the Laundrie motives could have been for not helping to find their son.
"We couldn’t find Gabby. We did anything to find Gabby. What did they do to find Brian? I haven’t seen them on any TV shows... find Brian. Why do you think that is."
Dr. Phil responded to say there were two explanations - either Laundrie was dead or his parents didn’t want him found.
Asked if they knew how his daughter had died, Joseph told Dr. Phil it wasn’t helpful for him to "go down that rabbit hole".
He said his daughter was a responsible adult and had been preparing for the trip for over a year and a half.
"This is not a 14-year-old girl going on a school trip here. So we respected her decisions. All of us tried to best prepare her. She knew what she was doing," he added.
"She’s gone, and to me, I need to find meaning behind it. I've got to find some good, some positive things to come from this."
Elsewhere in the interview, Gabby's mom said she had a gut instinct her daughter was dead when they learned Laundrie arrived back in Florida with their van but without her on September 1.