SALT LAKE CITY, UT -

A Utah man pleads guilty to the murder of a Southwest Virginia boy more than three years after he died.

35-year-old Nathan Sloop was in court in Salt Lake City Tuesday, where he pleaded guilty, but mentally ill, to aggravated murder in the death of his stepson Ethan Stacy.

Ethan died in 2010 just days after he arrived in Utah for a court-ordered visit to see his mother, Stephanie Sloop, for a week.  Ethan lived with his father in Richlands, Virginia.  His father was present in court for Sloop's plea.

Court documents say "severe abuse" between April 29th and May 8th was Ethan's cause of death.  Defense attorneys argued Ethan didn't die of abuse, but of dehydration.

By agreeing to plead guilty, Sloop avoided a possible death sentence.  Instead, he was immediately sentenced to 25-years to life in prison.  In exchange for his plea, several other charges Sloop faced were dismissed. 

Ethan's mother, Stephanie Sloop, is also charged with aggravated murder in his death, among other charges.  She has a court hearing in Utah set for February 11th.