Nunez made the admission during a four-hour video confession in Aug., 2012 that was played in court Friday, according to the Morning Call report.
Nunez, who dumped Cardoza's body along Lanze Lane in Salisbury Township also admitted Friday that he drank four alcoholic beverages and smoked synthetic marijuana before committing the alleged murder, according to a report on Lehigh Valley Live.
Nunez is on trial in Lehigh County Court for the July 5, 2012 killing of Cardona.
Defense attorney Glennis Clark Jr. hopes to convince the jury that his client's condition at the time of the homicide spares Nunez a first-degree murder conviction, which carries a sentence of life in prison.
Clark hopes to get his client off with a third-degree murder conviction.
Cardona's body had been found by the evening of July 5, 2012 in the 2700 block of Lanze Lane. When police arrived, they saw her "badly beaten body," which was about 15 feet from the road, according to an arrest affidavit.
An autopsy by the Lehigh County Coroner's office revealed Cordona died sometime after 7 p.m. July 4, 2012 of blunt and sharp trauma. According to the arrest affidavit, the wounds on her hands and arms were believed to have been "defensive wounds."