A Closer Look at the DNA Link Between the Graham & Harrington Cases

Sep 30, 2014

State police say the arrest of Jesse “LJ” Matthew has provided a forensic link to the case of Morgan Harrington, the 20-year-old Virginia Tech student who disappeared from the University of Virginia during a concert there in 2009. WVTF talks with experts on science and the law to find out what that might mean for Matthew, who’s now accused of kidnapping Hannah Graham. 

Credit Galveston County Sheriff's Office

  

Forensic evidence refers to any information obtained by police through scientific methods. It could be ballistics, fingerprints or DNA. And when it comes to DNA, there are two kinds – one more useful than the other. From blood, semen or perspiration, for example, UVA Biology Professor Doug Taylor says you can get nuclear DNA.

“Your nuclear DNA is unique to any other person in the world, except for an identical twin.”

From hair, scientists can extract a different kind of DNA – mitochondrial – which contains a lot less information.

“I might be able to tell geographically which regions of the globe you’re more likely to have come from.”

Taylor’s DNA, for example, would tell you his ancestors came from Northern Europe – not from sub-Saharan Africa, so it does enable police to rule some suspects out.

In the Harrington case, the DNA might have come from the victim’s T-shirt, found a few weeks after she disappeared, but Taylor says it could also have come from a farm field where her remains were found more than three months later.

“DNA can survive a long time – not like Jurassic Park necessarily, but scientists have sequenced the entire Neanderthal genome.”

Whatever police have in the Harrington case, legal experts say reasonable doubt could remain.

Dierdre Enright is Acting Director of the Innocence Project at the University of Virginia’s law school.

“There’s also the issue of whether or not other people were involved – whether it was Jesse Matthew on his own or if he had cohorts in this, and nobody seems real clear on that, and there’s also an issue of whether it’s benign.”

In other words, there could be another explanation for how Matthew and Harrington came into contact – an explanation that doesn’t involve a crime. She was last seen hitch-hiking. He, at the time, was believed to be driving a taxi.

Then, Enright says, it’s possible the crime lab made a mistake, as they did with an earlier case involving the murder of a child.

“They uncovered 11 fibers from a man’s van and said that was the absolute link to a piece of clothing that the victim had, and then months went by. The guy in jail denied, denied, denied.

And then months later another little girl was murdered in the same way. Then they took those fibers to the FBI lab, and they said not only are these not matches, all 11 of them did not belong to that item of evidence.”

But she doubts that’s the case this time.

“I would be very surprised if they made a mistake in a case like this where everyone is watching.”

Some years ago police tied DNA from the Harrington case to a rape in Northern Virginia. Police in Fairfax are not commenting on this new link, and Enright says they may not need to bring charges if a prosecutor in Charlottesville gets a conviction.

“If they got a sentence that was life without parole, there would be no need on the part of the prosecutors to assure someone being removed. I think it would probably also have a lot to do with what the victim wants to do.”

Mathew is scheduled to appear in General District Court Thursday at 10 for a bond hearing. He will do that by way of a video link to the regional jail. Volunteers with expertise in search and rescue are now working with tracking hounds in southern Albemarle County – still hoping to fnd Hannah Graham.