NORTHAMPTON, Mass. (WWLP) – An Amherst man has changed his plea to guilty for a charge in connection to the death of his four-month-old baby that died after being given adult sleep medication.

Isaac Villalobos, 35, of Amherst, also known as Angel M. Carattini-Rivera, pleaded guilty Wednesday in Hampshire Superior Court for assault and battery on a child causing substantial injury. The judge accepted Villalobos’ change of plea, according to Northwestern District Attorney Spokesperson Laurie Loisel.

Villalobos will serve five to seven years in prison. As part of an agreement between the Assistant District Attorney and Villalobos’s defense attorney, charges of manslaughter, reckless endangerment of a child and assault and battery with a dangerous weapon on a child under 14 were dropped.

“This was a horrific tragedy. In this case, the Commonwealth wanted to provide a measure of closure for the victim’s family while also holding the defendant accountable for his actions. We feel the best interests of justice were served with this plea and sentencing today,” said Assistant District Attorney Andrew Covington.

Villalobos was arraigned in July 2022 following a three-year investigation into the death of his infant son, who died on September 15, 2019 after receiving adult sleep medicine. The cause of death was determined to be acute doxylamine intoxication.