An autopsy on the body of real-estate broker Linda Stein, who was allegedly killed by her assistant Natavia Lowery at the end of October, has revealed that there was no marijuana in her system at the time of her death. This rips a hole in Lowery's defense strategy, as she has claimed she was driven into a rage after Stein yelled at her and repeatedly blew marijuana smoke into her face. It was that incensed rage, Lowery said, that led her to shatter Stein's skull with a yoga bar. But police sources told the Post that even a small amount of marijuana would have showed up in her system, and the toxicological tests on Stein's body, completed last week, revealed nothing. (Lawyers for Lowery say that she "made things up to get out of the interrogation room," including the marijuana-smoke story, and even the murder confession.) This is good news for prosecutors, who are trying to build up a narrative that Lowery had been using her boss' credit cards and bank accounts and killed her when she was caught. But it raises the question: Why did it take over three months for toxicology reports to come in on her death and just ten days for Heath Ledger's? Not that we're surprised that his got rushed through after all the public scrutiny, but that's an awfully big time difference. We fully expect an offensive Sean Delonas cartoon about this matter in "Page Six" tomorrow, most likely involving some bodyguards pushing around some wimpy gay forensic scientists, at the orders of a skeletal Mary-Kate Olsen.

SLAY EXCUSE BLOWN [NYP]