Cynthia Coffman was born in St. Louis, Missouri. When she was still young, her father left the family. This left her mother to raise Cynthia and her brothers alone. At one point, her mother even tried to give Cynthia and her brothers away. By the time Cynthia was 18, she had married and become a mother herself. However, her marriage did not last long. 

After the divorce, she moved to Arizona with a friend. It was there that she met James Marlow, who had just been released from jail.

Cynthia and James quickly became close and started using methamphetamine together. They eventually got married. Sadly, their relationship led them down a dark path, and they began committing violent crimes together.

Cynthia Coffman and her boyfriend, James Marlow, committed a series of brutal crimes in late 1986. They kidnapped and murdered four women over the span of two months. Their first victim was Sandra Neary, a 32-year-old woman from Costa Mesa, California, on October 11. They then took the life of Pamela Simmons, who was 35, on October 28 in Bullhead City, Arizona. 

Just a week later, on November 7, they killed 20-year-old Corinna Novis from Redlands, California. Their final victim was 19-year-old Lynel Murray from Huntington Beach, California, on November 12. The authorities arrested Coffman and Marlow on November 14, 1986. Following her arrest, Coffman confessed to the murders. During the trial, Coffman's lawyers argued that she was deeply in love with Marlow and that he had abused, brainwashed, and starved her, making it impossible for her to leave him when the killing spree began.

The trial took place in July 1989, and by 1990, both Coffman and Marlow were sentenced to death. Coffman became the first woman to receive a death sentence in California since the death penalty was reinstated in 1977. In a separate trial in 1992, Coffman was convicted of another murder, leading to an additional life imprisonment sentence. To this day, Coffman is sitting on death row in Central California Women's Facility, awaiting her execution.