(NewsNation) — A notebook reportedly belonging to Brian Laundrie, in which he claims responsibility for killing Gabby Petito in September 2021, was publicly released by the Laundrie family attorney Friday.

There is at least one other Brian Laundrie confession, according to the attorney for the Petito family.

Patrick Riley told NewsNation’s Brian Entin that there is more evidence in the possession of the Laundrie’s attorney, including a letter from Roberta Laundrie to her son Brian that apparently reads “burn after you read this” on the envelope.

Riley said the letter was not within the notebook released today, but it was a separate letter.

“It’s a pretty interesting, pretty odd letter,” Riley said. There is no date on the letter, but it appears that the letter was written within the time that Petito was murdered and Brian Laundrie committed suicide.

Riley said there was an offer in the letter that had to do with Gabby, but he declined to comment further.