Gregory Matthew Miley was born on November 22, 1960, in the United States. He grew up in an unstable home environment, experiencing neglect and a lack of proper education. Reports indicate that Miley was illiterate, had a low IQ of 56, and struggled socially from a young age. His mother had a turbulent personal life with multiple relationships and reportedly did not provide consistent care or supervision.

As a result, Miley spent much of his youth drifting and engaging in petty crimes. Seeking belonging and protection, he gravitated toward older men who offered attention and guidance. This vulnerability made him susceptible to manipulation, particularly from individuals like William Bonin, who exerted control over younger accomplices.

In 1980, Miley met Bonin in Southern California. To Miley, Bonin represented a father figure and protector. The two developed a sexual relationship, and Bonin soon involved Miley in his horrific pattern of abductions and murders. This marked Miley’s entry into violent criminal activity.

Gregory Miley’s participation in murders occurred during a short but deadly period in early 1980. Alongside William Bonin, Miley was directly involved in the kidnapping, sexual assault, and murder of two boys: Charles Miranda (15) and James Macabe (12).

On February 3, 1980, Bonin and Miley picked up Charles Miranda near a nightclub in Hollywood. Miranda was sexually assaulted in Bonin’s van and brutally beaten. Despite Miranda’s desperate pleas for his life, Bonin and Miley continued the attack, ultimately strangling him to death. Hours later, the pair abducted 12-year-old James Macabe, who was lured into the van with promises of drugs and a ride to Disneyland. Macabe endured severe physical and sexual abuse before being strangled and discarded at a construction site.

Miley’s role in these murders was significant, he not only helped restrain and assault the victims but also assisted in disposing of their bodies. In August 1980, police arrested Miley in Texas after recorded phone conversations revealed his participation in the killings. He was extradited to California, where he faced two counts of first-degree murder.

In May 1981, Miley pleaded guilty to both murders to avoid the death penalty. He received two concurrent life sentences with a minimum of 25 years before parole eligibility. Miley was incarcerated at Mule Creek State Prison in California, where he remained for decades.

On May 24, 2016, another inmate assaulted Miley in the prison yard, causing severe head injuries. He succumbed to his injuries two days later, on May 26, 2016, at the age of 55. His death marked the violent end of a life shaped by neglect, manipulation, and participation in one of California’s most infamous serial killing cases.