Judge Douglas Herndon told a weeping Colleen Rimer that her 4-year-old disabled son did not die because she left him in an SUV in 2008.
Jason Rimer died because for 17 hours, "nobody cared enough to go find him," the judge said.
Herndon told Colleen Rimer she "failed as a mother" on June 8, 2008, and then sentenced her to five to 20 years in prison.
Jason was left in a Ford Excursion about 2 p.m. after returning home from church with his mother and several siblings.
The boy was unable to unlock car doors because of his disability, myotonic dystrophy, a genetic muscular disorder that crippled his body and mind.
Jason died from heat stress, which could have taken three to five hours in the estimated 130-degree temperature in the vehicle.
Colleen Rimer and her husband, Stanley, were convicted March 1 after a two-week trial on charges that included involuntary manslaughter for Jason's death.
The parents also were convicted of child abuse and neglect for physically abusing five of their eight children and letting them live in squalor.
Colleen Rimer, 43, cried throughout Thursday's sentencing hearing, her voice barely audible as she fought through tears to address the judge.
"I am very sorry for the mistake I made. I wish I could change (it). I wish I could. There's nothing I can do. I will live with this for the rest of my life," said Colleen Rimer, who maintained from the beginning of the case that she was responsible for leaving Jason in the vehicle.
The judge said he was sympathetic to Colleen Rimer, who suffered from the same disability as her son Jason. But "the depth of neglect that occurred not for one hour, two hours, three hours, four hours, five hours, 10 hours, 15 hours, (but for) 17 hours," Herndon said, "that is inexcusable. That is unconscionable, what happened to that child on that day.
"Yes, that day you failed as a mother. You failed as a parent. You failed as a human being. Just like your husband did," the judge said.
During an emotional speech, defense attorney Michael Sanft tried to show how Colleen Rimer was manipulated and controlled by Stanley Rimer. Her actions that day were to attend to her husband's needs, not the children.
Stanley Rimer has maintained since his son's death that he was unaware Jason was in the vehicle. He said he was ill that day and left church before his family, spending the rest of the day in his bedroom.
Colleen Rimer spent the day with him, only leaving the bedroom once or twice.
Sanft pointed to letters the couple had sent to each other. While Colleen Rimer would tell her husband she loved him and supported him, Stanley Rimer would order her to stick to the story that Jason's death was solely her fault.
Sanft added that Stanley Rimer's manipulation of his client could be seen in that she had eight children despite her medical condition, which makes it difficult for her to perform normal physical functions on a daily basis.
Herndon agreed: "I think he was an overbearing bastard of a husband."
But prosecutor Marc DiGiacomo said Colleen Rimer hasn't learned anything from the whole ordeal. In a pre-sentencing interview, Colleen Rimer was still making excuses for her husband, DiGiacomo said.
The prosecutor asked Herndon to sentence Colleen Rimer to the same prison term as her husband. Stanley Rimer was sentenced in May to eight to 30 years in prison.
Herndon said he saw the two defendants differently. "I don't doubt the sincerity, (unlike) your husband, of your remorse for what happened to your child," the judge told Colleen Rimer.
Herndon told her he disagreed with her "greatly" for standing up for Stanley Rimer and said he hoped she would one day have an "epiphany" about their relationship.
The judge added that he understood wanting to support a spouse, but no one could condone what Stanley Rimer did to the children, which included hitting them with boat oars as punishment.
Colleen Rimer was given nearly two years credit for time already served, meaning she could be eligible for parole by 2014.
Afterward, Sanft said Colleen Rimer was willing to admit her guilt in the case from the very beginning, but prosecutors insisted she plead to a second-degree murder charge.
Sanft said he couldn't let his client plead guilty to an excessive charge and took the case to trial. A jury agreed and handed down an involuntary manslaughter conviction for both parents.
Meanwhile, Stanley Rimer has said he's written a book of scripture which he is submitting to the hierarchy of the Mormon faith.
After the trial, several of the Rimer children sent letters to Herndon asking him to show Colleen Rimer mercy, but were ambivalent about what the judge should order for their father.
Four Rimer children testified during the trial that the family home was filthy and cluttered. The children had a constant lice infestation and said their father performed corporal punishment on them.
Contact reporter Francis McCabe at firstname.lastname@example.org or 702-380-1039.