Police don’t believe Dr. Conrad Murray’s version of what happened the day Michael Jackson died. For one thing, “lethal levels” of propofol were found in the singer’s system, but Murray claims to have only given Jackson 25 milligrams. “It doesn’t make any sense,” Dr. John Dombrowski, a member of the American Society of Anesthesiologists told the Los Angeles Times. “I cannot believe that was the number that was given. Such a small amount won’t tip anyone over in terms of respiratory depression.” Medical experts say it takes approximately 400 milligrams of Propofol for someone of Jackson’s size to sleep for 8 hours — so it’s believed Murray gave Jackson more than 400 milligrams, on top of the other drugs he’d already administered. Not only that, but Murray admitted to giving Jackson 50 milligrams of propofol on a daily basis for several weeks before he died, but was worried that he might get addicted and cut back to 25 milligrams. This means Jackson already had an immunity to a much higher dose than Murray claims to have given him on the day he died. Dr. Scott Engwall, vice chair of anesthesiology at UC Irvine’s School of Medicine, said that for an average person without a high tolerance to drugs, 50 milligrams of propofol might be enough to make them doze off for 5 to 10 minutes, but for someone like Jackson, who had been using it nightly, it might be enough to close his eyes briefly — or it might not work at all. The police also don’t believe Jackson was alive when the 911 call was made — paramedics say when they arrived they believed Jackson had been dead for at least an hour.