Nathan Sloop told the judge that "reckless indifference" described his state of mind in the months before Ethan's death. He said he wanted to plead guilty on Tuesday to accept responsibility for his actions.
"I want to apologize to all those who were affected by my reckless indifference to Ethan Stacy," Sloop said.
Sloop also pleaded guilty but mentally ill to aggravated assault by a prisoner for attacking a David County jail officer. A number of other charges were dismissed as part of a plea deal, which also spared him from facing the death penalty.
Sloop was immediately sentenced to 25 years to life in prison on the murder count, and 1 to 15 years for the aggravated assault. The judge ordered the two sentences to run concurrently.
Davis County Attorney Troy Rawlings told Dawson on Tuesday that while Ethan's father, Joe Stacy, was in the courtroom, he was too emotional to make a statement before the sentence was handed down.
"It was a very traumatic experience for them to come on a plane and come to Utah," Rawlings said of Joe Stacy and his wife, who live in Virginia. "He felt the need and desire and the want to be here for his son."
Rawlings told the judge that the plea negotiation minimizes the risk of appeal, adding that evidence suppression issue and constitutionality issues also played a part in fashioning the plea deal.
Attorneys stipulated that while Sloop was mentally ill at the time Ethan died, he is no longer mentally ill.
Sloop's attorney, Richard Mauro, said his client's mental illness coupled with a high number of prescription painkillers and other medications Sloop was taking at the time led to his indifference to the child's life.
"I do not think that Mr. Sloop wanted Ethan Stacy to die or intended for him to die," Mauro told the judge.
The courtroom Tuesday was filled with Layton City police officers who investigated the child's 2010 death. Chief Terry Keefe said outside of court that this was an extremely difficult case for the law enforcement involved.
"We were here to support Joe and his wife," Keefe said. "This was a horrendous case … There are some things in law enforcement you don't forget."
Sloop was originally charged with aggravated murder, intentionally inflicting serious physical injury on a child, obstructing justice and abuse or desecration of a human body.
Sloop's wife and Ethan's mother, Stephanie Sloop, 31, has been charged with essentially the same counts as her husband, but prosecutors have not said whether they intend to seek the death penalty for her. She is scheduled to appear in court next Tuesday for a status conference. Prosecutors would not discuss Tuesday afternoon whether a plea deal was in the works for the woman.
Charging documents state the Layton couple engaged in multiple acts of "severe abuse" between April 29 and May 8 in 2010 that led to Ethan's death, including "beatings, burning, drugging, isolating, malnourishing, leaving the child alone and unattended while suffering, and refusing to seek vital life-sustaining medical attention."
The couple who said they left the injured boy in a locked bedroom while they got married on May 6 reported Ethan missing to police on Mother's Day, May 10, after discovering the boy was dead. But after a 12-hour search, police say the couple confessed to burying the boy near Powder Mountain Ski Resort in Weber County.
Nathan Sloop, who led officers to the body on May 11, told police he used a hammer to disfigure the boy's face and teeth in an effort to hinder identification.
Sloop had initially faced the possibility of the death penalty because Davis County prosecutors had invoked Shelby's Law and filed amended charges against Sloop, alleging he was "a major participant" in Ethan's death, and that he acted with "reckless indifference to human life."
But defense attorney Mauro had planned to challenge the constitutionality of Shelby's Law. He has contended that the death penalty is reserved for only "the most heinous" murderers, adding that not every murder case is eligible for the death penalty unless there is some aggravating factor.
"Somebody that didn't intend to kill somebody can't be in that category with the heinous murderers," Mauro has said.
Shelby's Law was named after 10-year-old Shelby Andrews, who died in 2006 in Syracuse after a year of abuse at the hands of her parents.
In an effort to control and discipline the girl, her father and stepmother beat her, forced her to eat her own feces and shut her inside a cramped linen closet.
Ryan and Angela Andrews did not face a potential death sentence because existing law didn't allow prosecutors to file aggravated murder charges unless they could prove the girl's death was intentional. The couple pleaded guilty to first-degree felony murder and each was sentenced to spend 15 years to life in prison.
Outrage over Shelby's death spurred Utah lawmakers to toughen the penalties for murdering a child, and in 2007 Shelby's Law was signed into law by Gov. Jon Huntsman.
Nathan Sloop's plea to aggravated assault by a prisoner stemmed from an unrelated case in which Sloop was accused of assaulting a deputy on Nov. 21. He was accused of punching the deputy in the face twice, attempting to gouge out the deputy's left eye and biting into the deputy's thumb. Charging documents said the deputy's thumb injury required "multi-layer sutures."