Brian Laundrie confessed in a posthumous note why he killed Gaby Petito

Brian Laundrie confessed to the murder of his girlfriend Gabby Petito in a notebook left behind in the Florida swamp where she killed herself, but insisted it was an act of "mercy ," according to the report released Friday.

According to Fox News, the confession recovered by the FBI in October, near Laundrie's remains, reads: "I ended his life."

" I thought it was merciful, that it was what she wanted, but now I see all the mistakes I made. I panicked. I was in shock," he said in part of the message.

He said he regretted the murder

The 23-year-old argued that he tried to put his girlfriend, to whom he was allegedly engaged , out of her misery after she fell and injured herself in the Wyoming desert, but said that after murdering her he immediately regretted his actions. .

Gaby Petito, originally from Long Island, disappeared on a road trip with Brian Laundrie and her strangled body was found at a campground near the Grand Tetons on September 19 last year.

Following the 22-year-old's death, Laundrie fled, sparking a nationwide manhunt for the then-suspected killer.

He committed suicide in a park

Brian Laundrie committed suicide by shooting himself in the head at Myakkahatchee Creek Environmental Park near Sarasota. In his posthumous confession note, he apologized and asked the authorities to go easy on his family.

"Please don't make life more difficult for my family," she wrote in the notebook. "They lost a son and a daughter. The most wonderful girl in the world. Gaby, I'm sorry," added Laundrie, who before committing suicide spent his girlfriend's money and went camping with his family while the victim's parents begged for information about his whereabouts.