Sweeney's trial began in August 1983 and was presided over by Judge Burton S. Katz. During the trial, Sweeney took the stand in his own defense. He testified that he had not intended to harm Dunne the night he arrived at her home. He claimed they had reconciled, were planning on moving back in together and had daily discussions about getting married and having children. On the night of October 30, Sweeney said that Dunne had abruptly changed her mind about a reconciliation and told him that she had been lying to him about getting back together and had been leading him on. At that point, Sweeney said he, "just exploded and lunged toward her." Sweeney claimed to have no recollection of attacking Dunne until he discovered he was on top of her with his hands around her neck. He then realized she was not breathing. Sweeney said he attempted to revive her by making her walk around, but she fell down. He then attempted to give her CPR which caused Dunne to vomit. Sweeney said that he also vomited, ran into Dunne's house, and consumed two bottles of pills in an attempt to kill himself. He returned to the driveway where Dunne was and lay down beside her. He said he then reached into her mouth and pulled her tongue out of her throat, something he had done for his epileptic father in the past. Sweeney's court-appointed attorney, Michael Adelson, said that his client's actions were not premeditated or done with malice. He maintained that Sweeney acted out in the "heat of passion", provoked by Dunne's alleged deception.