Mary Mabel Bennett was born on March 9, 1883, to parents Charles and Johanna Bennett in Hoosick, New York. Her father, Charles, struggled with mental illness and alcoholism, which made it hard for him to keep a job. This situation led to a difficult home life for Mary. Reports indicate that her father was abusive and that he even tried to kill her on several occasions.

At the young age of 15, Mary married Marcus Rogers. It was said that she was immature and often restless. Whenever she felt upset with her husband, she would leave home for a time, seeking space from their problems. In 1901, Mary gave birth to a daughter. Tragically, when the child was just six months old, Mary rushed into a neighbor's house, sobbing that she had dropped the baby. The baby later died from a fractured skull. Marcus's family suspected that Mary might have harmed the child intentionally. Their suspicion grew after Marcus fell ill after drinking tea that Mary had made for him. Following these events, Mary moved out of their home, although her husband wished for reconciliation.

Mary Mabel Bennett Rogers was involved in a plot to kill her husband, Marcus Rogers. In August 1902, while she was living in Bennington, Vermont, she began a relationship with Leon Perham, a laborer. With Perham's help, Mary planned to murder her husband. They met Marcus at a picnic grove on the evening of August 12. During the picnic, Mary acted as if she wanted to reconcile with him.

Mary proposed a rope trick to her husband. She tied his wrists, but he broke free easily. Then, when Marcus was distracted, Leon bound his wrists behind him, and this time Marcus couldn’t escape. Mary took out a vial of chloroform and forced Marcus to breathe it in for 20 minutes until he stopped struggling. After making sure he was dead, Mary took his life insurance payment book and they rolled his body into the nearby river. To make it look like a suicide, Mary placed his hat on a tree with a forged note.

The investigation into Marcus's death began after his body was found. Leon Perham confessed to his role in the crime and became the key witness against Mary at her trial in 1904. As a result of his testimony, he received a life sentence instead of the death penalty. Mary was found guilty of first-degree murder and sentenced to death by hanging.

After her conviction, there were many attempts to reduce her sentence. State Representative Frank C. Archibald introduced a bill to change her death penalty to life imprisonment, but it failed in the House. A resolution was put forth to investigate her mental state, but it too did not pass in the Senate.

Eventually, on May 30, 1905, Governor Charles J. Bell issued a reprieve for Mary to allow her case to be reviewed by the United States Supreme Court. The Supreme Court upheld the lower court's ruling, meaning her execution would go forward.

Mary's execution was set for December 8, 1905. On the day before, she asked about the gallows being built. On the day of her execution, Governor Bell considered an appeal but found no new evidence. He allowed the execution to proceed. Mary was hanged at the Vermont State Prison and pronounced dead at 1:17 PM. The hanging was reportedly botched, causing her to suffer before she died.

She was buried at St. Mary's Cemetery in Hoosick Falls, New York. Efforts were later made to place a monument in her memory, but it was refused at the request of her family, who did not want any memorial for her.