Michael Jackson's fingerprints were not on the bottles of propofol found in his bedroom, ABC News reported based on interviews with anonymous sources close to the investigation.

If true, that information could destroy the defense's argument that Dr. Conrad Murray gave Jackson a safe dose of propofol, and that Jackson then took an additional, lethal dose of propofol and the sedative lorazepam while Murray was out of the room.

The trial isn't over yet, but so far, the testimony against Murray has been consistently damning.

In addition to the new evidence that it was, in fact, Murray who administered the lethal dose of propofol, a previous witness testified that after Murray found Jackson unresponsive, he told one of Jackson's aides to hide certain medical supplies before calling 911. Another witness said that when Jackson and Murray arrived at the hospital, Murray did not inform the doctors that he had given Jackson propofol.

According to multiple witnesses, by the time Murray returned to the bedroom and found Jackson unresponsive, there was no way to save him, even if he had called 911 immediately.

There was no CPR, there was no doctor, no paramedic, no machine that was going to revive Michael Jackson, defense lawyer Ed Chernoff told the court. He died so rapidly, so instantly, he didn't even have time to close his eyes.

Murray maintains that the dose of propofol he administered, combined with the doses of propofol and lorazepam that he claims Jackson administered, created a perfect storm in his body that killed him instantly.

But prosecutors say Jackson was killed by Murray's dose of propofol alone. They accuse Murray of negligence for not monitoring Jackson's vital signs and making sure someone was in the room with him at all times, and also for giving him propofol to begin with. Propofol is a powerful anesthetic that is normally used in hospital settings, not at home.

Murray is accused of involuntary manslaughter and could face up to four years in prison if convicted.