The parents of Brian Laundrie, a Florida man considered the lone person of interest in the murder of his fiancee Gabby Petito, have asked the FBI to hand over a notebook that was found in a nature preserve near their son’s remains.

Laundrie died from a self-inflicted gunshot wound while hiking in the Myakkahatchee Creek Environmental Park in North Port, Florida, in September, but his skeletal remains were not found until late October. A notebook was among the items of Laundrie’s found nearby.

Petito’s body was found in September near Grand Teton National Park in Wyoming after the couple had gone on a cross-country road trip.

Attorney Steven Bertolino is trying to get the notebook back for Laundrie’s parents, citing it as an estate matter, according to WFLA. Bertolino said the FBI is expected to return the notebook after closing the case.

Laundrie’s parents are also attempting to be named beneficiaries of his estate, which is believed to consist of at least one bank account with several thousand dollars deposited.

Bertolino said he is also trying to get items returned to Petito’s family.

“Nichole Schmidt filed to obtain Gabby’s belongings that are in the Laundrie home or in police custody,” he said. “Rick Stafford (the Petito family attorney) and I are trying to work this out cordially.”