Evidence of a problem
DNA clue in Tessa slay case ‘not conclusive’
A grand jury will soon weigh the case against two teen suspects in the murder of Tessa Majors — but what was once hoped to be the key evidence against them is actually far from conclusive, sources told The Post.
DNA testing ostensibly implicating the 14-year-old boy suspected of fatally knifing the Barnard College freshman hasn’t yielded the outcome investigators were looking for, sources said.
It shows a 1 million to 2 million likelihood ratio of the DNA being the teen’s, sources said — a far cry from the 5 billion figure investigators prefer to have anchoring a murder case.
“That’s a very low match. That means some of the stabber’s DNA structure matches some of the DNA” recovered as evidence, said one NYPD insider. “The 1-2 million [figure] is not conclusive that the stabber is the one who left his DNA.”
Factors including exposure to the elements — and the DNA of others — can degrade the sample and cause lower likelihood ratios, the source explained.
Two other law-enforcement sources concurred that the DNA evidence is not conclusive, and while authorities still intend to present it for the consideration of a grand jury, it will likely be less as a smoking gun and more as one facet of the case.
Still, a forensics expert argued that the results of the testing are hardly a death knell for the case.
“They want to say it’s unique,” Lawrence Kobilinsky, a professor of forensic science at the John Jay College of Criminal Justice, said of the DNA and authorities.
But “there are plenty of people convicted without a unique match. It’s nice if you’ve got 5 billion, but not needed.”
Majors, 18, was cutting through Morningside Park in Manhattan on a dark December afternoon when she was cornered by three assailants, one of them waving a knife, authorities have said.
The group tried to rob the aspiring journalist, but she fought back, chomping down on the armed attacker’s finger in their fatal struggle, sources have said.
There is no known footage of the attack, save for a grainy surveillance video from a camera outside the park that rendered the run-in clear enough to convey the gist of what happened but not to reveal any faces.
There also were no known impartial eyewitnesses.
Zyairr Davis, 13, was the first to be charged in the case, accused by prosecutors in Family Court of felony murder.
He has purportedly admitted to playing a role in robbing Majors but has maintained that one of the two 14-year-old pals with him at the time plunged the knife into her, officials said.
As for those two teens, cops have brought each of them in for an interview but ultimately released them without charges.
The Post is withholding their names.
A search warrant executed at home of the 14-year-old suspected of stabbing Majors yielded an empty plastic baggie like those commonly used by drug dealers, sources said.
Cops showed the baggie to a local pot peddler, who allegedly recalled selling it to Majors shortly before her murder, sources said.
When cops briefly detained the suspected stabber for questioning, he submitted to a cheek DNA swab, sources said.
But the sources now say that testing is inconclusive.
It remains unclear what evidence, if any, may have been culled from a knife found in the park, which sources first indicated last week is the murder weapon.
Authorities aren’t taking any chances, preparing a massive trove of evidence to take to a grand jury, sources have said.
“They feel they have enough evidence to get an indictment,” said an insider.