The final witness to appear for the prosecution, forensic psychiatrist Park Dietz, began his testimony on February 12. Dietz testified that he did not believe Dahmer to be suffering from any mental disease or defect at the time that he committed the crimes, stating: "Dahmer went to great lengths to be alone with his victim and to have no witnesses." He explained that there was ample evidence that Dahmer prepared in advance for each murder, therefore, his crimes were not impulsive. Although Dietz did concede any acquisition of a paraphilia was not a matter of personal choice, he also stated his belief that Dahmer's habit of becoming intoxicated prior to committing each of the murders was significant, stating: "If he had an impulse to kill or a compulsion to kill, he wouldn't have to drink alcohol to overcome it. He only has to drink alcohol to overcome it because he is inhibited against killing."