Gary Michael Hilton was born on November 22, 1946, in Atlanta, Georgia.

On October 21, 2007, John and Irene Bryant, a retired couple from North Carolina, went hiking in the Pisgah National Forest. They were reported missing after family members had not heard from them for two weeks. The authorities launched a search using volunteers, cadaver dogs, and helicopters. During the investigation, it was discovered that John had attempted to call 911 but lost the signal.

On November 10, 2007, the search team found Irene's body on a trail, hidden under leaves. She was confirmed to have been killed with a blunt object. The FBI took over the investigation when they learned that a bank card belonging to the Bryants had been used after their disappearance, captured on surveillance by a man in a yellow rain jacket. Later, on February 3, 2008, a hunter found John's skull along with other remains in a different part of the forest.

Cheryl Dunlap, a 46-year-old woman from Florida, was reported missing on December 4, 2007, after she failed to attend her Sunday school class. Her abandoned car was found the next day. A search party that included about 180 people looked for her but could not find any clues initially. On December 16, her decapitated body was discovered in the woods, and DNA testing confirmed her identity. Her ATM card had been used multiple times after her disappearance, leading detectives to seek a suspicious man driving a green truck.

Meredith Emerson, a 24-year-old, went for a hike on January 1, 2008. Witnesses saw a man with a dog following her. A few days later, belongings belonging to her were found in a dumpster, and search efforts intensified to find her. Soon after, police identified Hilton as a person of interest and arrested him on January 5. He was charged with kidnapping her.

After his arrest, Hilton agreed to disclose the location of Emerson's remains in exchange for a plea deal. He admitted to killing her and was sentenced to life in prison with the possibility of parole after 30 years. Later, he was charged with Cheryl Dunlap's murder and was convicted after a trial. He claimed to have abducted her from a geological area, held her for two days, and then killed her. The jury convicted him on several counts, and he was sentenced to death in Florida.

In 2012, Hilton pleaded guilty to the murders of John and Irene Bryant, detailing how he killed Irene and then abducted John to get financial information before killing him too. He received an additional life sentence without parole for these crimes. Hilton has been linked to several other unsolved cases and remains a suspect in other murders.