Mark William Cunningham was born on January 27, 1960, in the United States. Not much is publicly documented about his early childhood or upbringing. What is known is that by the early 1980s, Cunningham was living in California and had formed a relationship with a teenage girl named Lynn Bohnen. The relationship reportedly began in 1981 when Bohnen was just 14 years old and Cunningham was 21.

On April 27, 1983, the body of Mark Cameron Ferrell was found in a burning vehicle on East Zayante Road in Santa Cruz. Authorities discovered that he had been shot multiple times before his car was set on fire. A .38 caliber bullet was found in his chest.

On June 7, 1983, the bodies of two men, Hon Mau Lee and Chen Chien Ying, were discovered by surfers on a trail near Laguna Beach. Both men had been shot multiple times. Their possessions remained untouched, suggesting the killings were random.

For nearly two years, the murders went unsolved. In November 1983, ballistics testing linked the same gun to all three murders. On January 3, 1985, a man reported that his friend, Mark William Cunningham, had confessed to killing three men.

Cunningham's former girlfriend, Lynn Bohnen, also came forward. She stated that she had been with him on the day of Lee and Ying's murders and that he had killed them. This information led to Cunningham's arrest.

Cunningham was charged with three counts of first-degree murder but pleaded not guilty. His trial began in January 1988. Bohnen testified against Cunningham, describing how he had pulled a gun on the two men before leaving the scene. The jury found him guilty of two counts of first-degree murder and one count of second-degree murder.

In April 1988, the jury sentenced Cunningham to life imprisonment without the possibility of parole. He was then transferred to Pelican Bay State Prison, where he remains today.