Dr. Arnold Klein was a shadowy presence at the trial of Dr. Conrad Murray, blamed by the defense for getting Michael Jackson addicted to Demerol, which they said contributed to his death from a self-injected fatal dose of propofol.
The judge didn't allow jurors to hear from Klein, Jackson's dermatologist, during the trial, but the doctor spoke exclusively to ABC News' Jim Avila during the first day of jury deliberations.
Klein flatly denied the defense assertion that he got addicted Jackson to the painkiller Demerol.
"You know the answer, sir. No. 'Cause there were no results that show, in toxicology reports, there was any Demerol in his body," Klein said. "All they found in his body were all the drugs that were ... given to him by Conrad Murray -- so I had nothing to do with addicting him to any substance."
During his opening statement, Murray attorney Ed Chernoff said Jackson received Demerol three to four times a week from Klein, but Murray knew nothing about these regular doses of Demerol.
Klein said he gave Jackson doses of the drug during facial reconstructive surgeries, but maintains he never gave the musician doses large enough for him to become addicted. Jackson never showed any signs of addiction or withdrawal from Demerol, he said.
The defense said Jackson was taking propofol to help him overcome the difficulty sleeping that can by caused by withdrawal from Demerol addiction.
Klein said he's being used as a scapegoat for Murray, who he said is an incompetent doctor responsible for the numerous needle marks found on Jackson's body after his death.
He also said it was irresponsible for Murray to give Jackson propofol at all, a statement echoed by the prosecution in court.
The defense argued that Murray was trying to wean Jackson off propofol as a sleep aid, and that Jackson's insomnia was exacerbated by an alleged addiction to Demerol.
Murray is accused of involuntary manslaughter in the 2009 death of the King of Pop. Jackson died at age 50 of an overdose of propofol, a powerful sedative Jackson used to fall asleep.
The jury, which heard from 49 witnesses and saw hundreds of pieces of evidence during the six-week trial, was given the case Friday.
In order to find Murray guilty, the jurors have to conclude he either committed a legal act with criminal negligence or failed to perform a legal duty with criminal negligence. If convicted, he faces up to four years in prison and the loss of his medical license.
"You must discuss the case only in the jury room," Judge Michael Pastor told the jury Friday -- and with that, Murray's fate was placed in the hands of seven men and five women.
The jurors didn't ask any questions or request any help during their first day of deliberations. There are some clues, however, about what makes the jurors tick, from questionnaires they filled out before the trial began.
Half the jury is white, five jurors are Hispanic, and one is African-American. The jurors include a postal worker, a TV director, a cartoon animator, and viewers of TV crime shows. Several said they watched the O.J. Simpson trial on television -- and now, 16 years later, they're in the same courthouse debating Conrad Murray's fate.
Several jurors are Michael Jackson fans, and half of them say they believe celebrities use stardom to bend the rules -- including getting away with crimes.
Jury deliberations are set to resume at 8:30 a.m. Monday.