Melissa Ann Shepard was born as Melissa Ann Russell on May 16, 1935, in Burnt Church, New Brunswick, Canada. She grew up in a small town, but not much is known about her early family life or childhood experiences.

Melissa eventually married her first husband, Russell Shepard. This marriage did not last, and they divorced after some time. She went on to have multiple marriages, which would later become significant in her life story.

Throughout her life, she faced several legal issues. From 1977 to 1991, she was convicted of over 30 fraud-related crimes. These convictions led her to serve time in prison. In 1992, she was convicted of manslaughter after a serious incident involving her second husband. This incident attracted significant attention and set the stage for her later life.

In 2000, she met her third husband, Robert Friedrich, online. They married shortly after they met. He died just over a year later, leaving her with a sizable amount of money. Melissa's relationships often ended dramatically, and her life was marked by a pattern that raised many questions. Melissa continued to interact with the law after these marriages and had additional legal troubles in the years that followed.

In 1992, she was convicted of manslaughter for the death of her second husband, Gordon Stewart. She ran him over twice with her car in 1991. He had tranquilizers in his system at the time. Shepard claimed that he had raped her and that she was trying to escape when she hit him. She was sentenced to six years in prison but only served two years before being released for good behavior.

In 2000, she met her third husband, Robert Friedrich, online and married him shortly after. He died 14 months later, and his sons accused her of causing his death by giving him an overdose of prescription medicine. She was never charged in connection with his death, but his sons were able to win back $15,000.

In 2005, Shepard met another man online in Florida. After he was hospitalized multiple times, his son notified the police. Tests showed that the man had tranquilizers in his system, but police could not prove that she poisoned him. Instead, she pleaded guilty to grand theft, forgery, and using a forged document, and was sentenced to five years in prison.

In 2012, she was charged with attempted murder of her fourth husband, Fred Weeks. She later pleaded guilty to lesser charges and was sentenced to three and a half years in prison. During this time, police discovered a stash of drugs in her possession as well as prescriptions from five different doctors and multiple identity documents.

On March 18, 2016, she was released from prison but had strict conditions imposed on her. Shortly after her release, she was found accessing the internet, which violated those conditions. Shepard was charged with breaching the terms of her release. In August 2016, her lawyer entered not guilty pleas for these breaches on her behalf, but the charges were dropped later that year.