Brian was named a person of interest in the homicide of the 22-year-old Long Island woman, who disappeared during a road trip the couple was taking across the country.
Her remains were found in a Wyoming national park on Friday, Sept. 19, eight days after her family reported her missing.
In a two-part interview with Dr. Phil, Gabby's father, Joseph Petito, and her mother, Nichole Schmidt, said they made multiple attempts to contact Brian Laundrie's parents while trying to locate their daughter, with no response.
They said at the time they were attempting to contact the Laundrie family, they were unaware that Brian, age 23, had returned to his parents' home in Florida on Wednesday, Sept. 1 with Gabby's van, and they were worried that both Brian and Gabby were missing.
Nichole Schmidt said she only learned the van was in Florida the night of Saturday, Sept. 11, when she reported her daughter missing.
Joe Petito said he believes Brian is hiding somewhere, calling him a "coward." Both Gabby's parents and stepparents asked Brian to turn himself in.
Gabby's parents said they believe Brian's parents know more information than they're sharing.
Law enforcement has been searching for Brian since his parents reported on Friday, Sept. 17, that they hadn't seen their son since Tuesday, Sept. 14.
"What did (Brian's parents) do to find Brian? They called the cops, haven't done a thing since. I haven't seen them on any TV shows to find Brian," Joe Petito said. "Why do you think that is?"
The FBI is asking people with information or sightings of Laundrie to call the agency at 1-800-CALL FBI or submit tips online here.
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