Marvin Lee Irvin was born on May 4, 1949, in St. Joseph, Missouri. He grew up in a family that rented a three-story home. Neighbors described Irvin as a quiet and polite boy. He attended school in Highland, Kansas, where he graduated from Highland High School.

After finishing high school, Irvin joined the St. Joseph Police Department in 1970 and became an officer. However, he did not stay long in this position and soon resigned. In April 1974, Irvin faced serious accusations. He was accused of raping a 15-year-old girl in Kansas after allegedly abducting her outside a drug store in St. Joseph. He was arrested, but the case was dropped when the girl decided not to testify.

Later in 1974, Irvin began a relationship with a girl named Ruth West. Their relationship had its challenges. When Ruth was only 15, she gave birth to Irvin's child. Ruth later described their relationship as abusive and said that Irvin was emotionally manipulative towards her.

Irvin and Ruth decided to marry in March 1979 after moving to California, but their relationship continued to deteriorate. Ruth claimed that Irvin physically abused her, leading her to flee with their son.

In 1979, Marvin Lee Irvin became a suspect in the disappearance of a young woman named Micki Jo West. On September 11, 1979, Micki was supposed to report to work at a hospital but did not show up. That same day, Irvin, along with his friends, forcibly took Ruth West and her son from a motel in Kansas, where they were hiding from him. The search for Micki raised suspicions around Irvin, but he passed several polygraph tests that did not yield conclusive results. In 1986, a letter surfaced claiming that Irvin had killed Micki Jo West, but no identifiable information was included, leaving the police unable to follow up on it.

Years later, Irvin returned to St. Joseph, Missouri. On September 1, 1990, Patricia Diane Rose went missing after a visit to a local bar. A tip led investigators to Irvin, who owned a truck that was searched. Inside, they found a blood-soaked towel linked to Patricia. Shortly after, on October 29, 1990, Crystal Lynn Simmons also vanished after being seen at a downtown bar. What began as a missing persons investigation soon revealed a darker story.

The remains of Patricia and Crystal were discovered months later in a cornfield. Autopsy results indicated that both women died from multiple blows to the head. While Irvin awaited trial, he initially denied involvement in their disappearances. Eventually, he changed his plea and confessed to the murders of all three women, including Micki Jo West. He even described the location where he buried Micki's body, leading authorities to search in Kansas. Despite their efforts, inclement weather delayed the search, and she was never found.

In October 1991, Marvin Irvin pleaded guilty to two counts of first-degree murder and one count of second-degree murder. He was sentenced to life in prison without the possibility of parole.