Marissa Suzanne DeVault was born on November 6, 1977. She grew up in a challenging environment. Details about her early childhood and family life are not widely available. However, it is known that she faced difficulties during her upbringing.

As a child, Marissa experienced abuse. Reports indicate that her mother physically abused her. She also claimed that her stepfather sexually abused her. These experiences of abuse likely had a significant impact on her life.

Marissa became a mother herself. She had several children but faced issues in her family life. At some points, she had to make difficult decisions regarding her children's custody, which was a source of conflict.

As she reached adulthood, Marissa struggled with her personal relationships. She married and eventually became a stay-at-home mother. However, her marriage faced problems, and her husband was reported to have been abusive toward her. 

On January 14, 2009, Marissa Suzanne DeVault attacked her husband, Dale Harrell, in their home in Gilbert, Arizona. She struck him several times in the head while he was asleep, causing severe injuries, including multiple skull fractures. Harrell was taken to the hospital for treatment. That night, DeVault claimed that an unknown assailant had broken into their home and attacked Harrell. However, police later found a blood-covered hammer at the scene, and DeVault was arrested on charges of aggravated assault.

After Dale Harrell died from his injuries on February 9, 2009, a grand jury indicted DeVault for first-degree murder. Following the incident, DeVault was assaulted while jogging the next day, which resulted in a broken jaw and ankle. During the investigation, police looked into a man living with DeVault, Stanley Cook Jr., but forensic evidence did not link him to Harrell's murder. Under further questioning, DeVault eventually confessed that she had used the hammer to beat her husband.

In the aftermath, DeVault submitted a 300-page confession to the police, alleging years of abuse at the hands of Harrell. She described incidents of physical and sexual abuse and stated that she had acted in self-defense on the night of the attack. However, detectives found no evidence to support her claims of abuse. DeVault's past was also scrutinized, revealing inconsistencies in her statements about her life, including a major lie about inheriting money from her stepfather.

DeVault's trial began in January 2014. Prosecutors argued that she killed Harrell to benefit from two life insurance policies totaling $1.25 million. In contrast, her defense claimed she acted out of self-defense due to years of abusive behavior from her husband. The jury ultimately found her guilty of first-degree premeditated murder on April 8, 2014. They determined that she had shown excessive cruelty, which made her eligible for the death penalty. However, in the sentencing phase, the jury decided to sentence her to life in prison without the possibility of parole, and on June 6, 2014, the judge confirmed the sentence.