Nathan Sloop entered the plea Tuesday in Farmington to charges of capital murder, child abuse, obstructing justice, and desecrating a body.
He and the boy's mother, Stephanie Sloop, are being tried separately on capital murder charges in the death of Stephanie Sloop's son Ethan Stacy. The child's disfigured body was found in the mountains of northern Utah in May 2010.
Prosecutors say the Sloops repeatedly beat Ethan and locked him in his bedroom for days until he died, then buried his body.
Nathan Sloop's pre-trial hearing is set for Oct. 9. Stephanie Sloop has a hearing set for July 31.
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