|Name||Sarah Jean Mason|
|Alias|| The Ice Queen|
Sarah Jean Dawes
|Family|| Unnamed father (deceased)|
Deb Mason (mother)
Jacob Dawes (husband; deceased)
Byron Sheffield (son)
|Portrayed By||Jeannetta Arnette|
|First Appearance||"Riding the Lightning"|
"I used to tell Riley, that no matter where we were, the man in the moon would be looking down on both of us."
Born in Florida, Sarah was the daughter of Deb Mason and her husband, and was described as a shy, quiet and smart child. A strict military man, Sarah's father abused his wife, but according to Deb, never laid a hand on Sarah, despite the two often not seeing eye to eye. Eventually, Sarah got a job as a housekeeper, working primarily for wealthy families in Hampton, and met a carpenter named Jacob Dawes, who she was attracted to due to, as she put it, seeing "freedom" in him. In reality, Jacob was sadistic serial killer, who torture-murdered teenage girls in his workshop, burying the bodies under it and the places he renovated. While Sarah had at least some knowledge of what Jacob was doing, she never did anything to stop him. In 1987, the two had a child, who they named Riley, and three years later, Sarah, overcome with guilt, made an anonymous call to the police, saying she had seen Jacob with several girls who were reported missing. After the police interviewed him, Jacob, intending to flee, told Sarah to kill Riley, believing him to be nothing more than a liability. Refusing to kill Riley, Sarah gave him to the Sheffields, a couple she cleaned for, afterward telling Jacob she had killed him and disposed of the body.
Three hours later, the police arrested Sarah and Jacob, after getting a search warrant and discovering the remains of twelve girls under Jacob's workshop. Sarah falsely confessed to murdering Riley, but never mentioned taking part in any of Jacob's murders, despite his claims that she brought him victims. Dubbed The Ice Queen due to her seemingly apathetic demeanor during the trial, Sarah, along with Jacob, was sent to the Florida State Penitentiary, and sentenced to death. Kept in isolation for her own protection, Sarah spent her time painting, some of her portraits being a river, a bouquet of roses (twelve, for each of Jacob's known victims) and Riley running through a meadow. When Riley, now known as Byron Sheffield, had an article written about him in a newspaper, mentioning a scholarship he had gotten for his cello playing, Sarah cut it out and hid it in a picture frame. In Riding the Lightning, Gideon and the BAU found Riley/Byron and intended to reveal his identity to save Sarah Jean from execution, but at the last minute Mason convinced Gideon that it will ruin Riley's life and the attempt was cancelled. Sarah Jean was given the death penalty, Gideon's face being the last she saw as per her request.