I think we all knew something was fishy about a scenario involving an Occupier behaving violently.

The DNA that investigators initially believed was recovered from skin cells on the slain woman’s portable compact disc player and from the chain found after the March protest came from a laboratory supervisor at the Office of the Chief Medical Examiner, the person briefed on the matter said.

“The O.C.M.E. tainted the samples and it was the O.C.M.E. supervisor’s whose DNA was on both,” the person said.

But Ellen S. Borakove, a spokeswoman for the Medical Examiner’s Office, said, “We’ve excluded all medical examiner personnel.” She added that the office was still working on the test.

I’m not sure where that leaves us, but the New York Post — which had this story front page earlier today — is also hearing from sources that it’s a bad sample:

“The DNA was contaminated,” a source said today.

“It was a total screw up,” said another.

Another law enforcement source familiar with the unsolved Fox case said it was highly improbable that there was a real connection between the material on the chain and the DNA on the CD player.

“What are the chances that the killer came in contact with this chain and left his DNA on it all these years later?” the source said.

The prime suspect has already been excluded as a source of the DNA. I can’t understand where the contamination could have come from, though, if the medical examiners have all been ruled out. Maybe a cop who worked the 2004 murder and handled the CD player also, as chance would have it, ended up working the case involving Occupiers and the subway gate? You would think they’d have protocols to eliminate obvious sources of contamination before leaking a bombshell scoop to the New York media about unsolved cases and the Occupy crew.