WFLA said the Laundrie family's lawyer, Steven Bertolino, confirmed that the family is working to recover the notebook, which was found near his remains in a Florida nature reserve in October.
Laundrie's manner of death was determined to be suicide.
Laundrie, age 23, was named a person of interest in the disappearance and death of his fiancée, 22-year-old Gabby Petito, whose remains were found in a Wyoming national park on Sept. 19, after she disappearing in late August.
The Teton County coroner determined that Petito had been strangled to death.
Gabby Petito's mother, Nichole Schmidt, has also filed to retrieve her daughter's possessions from the Laundrie family's home.
Bertolino told NewsNation now that he and the Petito family's lawyer are "trying to work this out cordially.”
Click here to follow Daily Voice Peekskill and receive free news updates.