TRENTON, N.J. (AP) — A state appellate court has upheld the aggravated manslaughter conviction of a New Jersey man who used a hammer to kill his mistress after she threatened to expose his double life, then dumped her dismembered body in a Staten Island pond.

Rosario DiGirolamo pleaded guilty to the charge just before he was due to stand trial in January 2011, after a judge refused to dismiss his indictment and suppress evidence. But as a condition of his plea, he retained the right to appeal the judge’s decisions.

The appellate court, though, rejected his claims in a ruling issued late this week.

DiGirolamo is serving a 25-year prison term for the June 2007 slaying of 27-year-old Amy Giordano of Hightstown. He also received probation for abandoning their infant child outside a Delaware hospital shortly after the killing..

Prosecutors say DiGirolamo kept his mistress of two years and their year-old son in an $850-per-month apartment above a nail salon in Hightstown while having a wife and son of a similar age living in a Tudor-style house in Millstone, about 20 miles away. Prosecutors said DiGirolamo, a computer analyst, killed Giordano after she demanded a more expensive apartment he couldn’t afford and threatened to tell his wife about their relationship.

When he entered his plea, DiGirolamo said he and Giordano had fought on the day of her death and that he struck her with a hammer as she lunged at him. Prosecutors say he chopped up Giordano’s body with a hacksaw after she was dead, then stuffed some of the remains in a suitcase and dropped it in the pond.

After dumping Giordano’s body, DiGirolamo drove their then-11-month-old son to the hospital, where the boy was discovered with a handwritten note pinned to his diaper that called him “John Vincent” and said his caregiver had no job or health insurance.

The boy was soon identified after a tipster recognized him as Giordano’s child.

Shortly after Giordano disappeared, DiGirolamo abandoned his family, quit his job and flew to Italy, where he remained for about six weeks before returning to face the child abandonment charges. He was later charged with first-degree murder and tampering with evidence, and his wife later divorced him.

Prosecutors said that while examining DiGirolamo’s computer, they uncovered Google searches including one for “lethal karate blows to the back of the head” made days before Giordano’s killing.

(Copyright 2012 by The Associated Press. All Rights Reserved.)

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