Morris Odell Mason was born on March 28, 1954, in Philadelphia, Pennsylvania. He spent most of his childhood in Northampton County, Virginia, where he was raised by his mother. As a child, Mason reported hearing voices that told him to "destroy things." Neighbors observed that he had a fascination with fires from a young age. His academic journey was marked by struggles, and he did not finish high school.

When he was 17 years old, Mason was first diagnosed with mental health issues. He was placed under involuntary psychiatric commitment at that time. He had various diagnoses over the years. He was identified as having developmental disabilities with an IQ measured at 66 in one assessment and 62 in another. Mason also received diagnoses of paranoid schizophrenia on three different occasions.

On May 2, 1978, Morris Odell Mason began a violent crime spree in Virginia. He burglarized the home of 86-year-old Ursula Stevenson in Birdsnest. After breaking in, he raped and murdered her. To hide his crime, he set her house on fire.

On May 13, 1978, Mason targeted another house, this time belonging to 71-year-old Margaret Keen Hand. He forced her to close her drapes and then engaged in a brutal attack, which included rape and beating her with an ax. After tying her up and nailing her wrist to a chair, he set the room on fire, leaving the scene. He returned later to retrieve a bag containing his identity papers.

The next day, on May 14, Mason broke into a home where two young girls, aged 12 and 13, were present. The 13-year-old tried to defend herself with her father's gun, but Mason wrested it away and shot her in the abdomen, causing her to become paraplegic. He then kidnapped the 12-year-old girl, taking her to a forest. There, he raped her, covered her with leaves, and set the leaves on fire, burning parts of her clothing and hair. Despite their injuries, both girls survived the ordeal. Later that same day, Mason burned down an abandoned house.

Mason was arrested the following day, on May 15, 1978. He later pleaded guilty to the charges related to Margaret Hand's murder. He received a death sentence and multiple life sentences for his other crimes.

His death sentence drew attention because of his mental health issues. Mason had been diagnosed with schizophrenia and intellectual disabilities. While on death row, Mason exhibited childlike behaviors. His execution took place on June 25, 1985. On the day of his execution, he had a last meal featuring multiple fast food items and even shared some with his guards. His final moments were marked by a lack of understanding about the situation he faced, raising concerns about his mental state. He was executed by electrocution, despite appeals for clemency based on his mental condition.