Could knife provide fresh DNA evidence in O.J. Simpson case?

A knife was handed in to Los Angeles police within the last month in relation to the O.J. Simpson case. Even if the weapon has anything to do with the case, is it likely to yield evidence?

Police in Los Angeles are examining a knife that may – or may not – be evidence related the trial of O.J. Simpson two decades ago, over the murder of his ex-wife and her friend.

The knife was recovered within the last month, according to a police statement Friday, handed over by a retired Los Angeles Police Department (LAPD) officer, who said he had been given the item by a construction worker claiming to have found it during the demolition of Mr. Simpson’s house in 1998.

The revelation raises a multitude of questions, such as why the item has been handed in now, after so many years, what impact it could have on the case, and what evidence could possibly be gleaned from it.

“Could it still contain forensic evidence of value? Yes,” says James Adcock of the Center for the Resolution of Unresolved Crime (CRUC), in a telephone interview with The Christian Science Monitor. “It depends on where it was, how it was handled, where it was stored.” 

The knife is currently being examined by LAPD’s forensics lab, but observers wonder why it has taken so long for the ex-officer concerned to hand it over, pointing to how the timing coincides with the airing of a TV show, "American Crime Story: The People v. O.J. Simpson."

The L.A. police spokesman, Capt. Andrew Neiman, himself cast doubt on the veracity of the claims, saying it has yet to be determined “whether or not this actual piece of evidence is in fact evidence or it’s just a facsimile or a made-up story”.

Moreover, it is not the first time a knife purportedly linked to the case has emerged, the murder weapon never having been found during the initial investigation.

But the police are nonetheless still interested in potential evidence, as the case remains open: “Unless there’s an actual arrest or conviction to prove that we have actually closed the case, cases [such as the O.J. Simpson and other murder cases or robbery cases] remain open,” explained Captain Neiman.

So, what is the likelihood of the knife yielding evidence, if indeed it was related to the murders?

“DNA only solves about 30 percent of all cases. Period. No more,” Dr. Adcock of CRUC tells the Monitor. “But there have been cases decades old where we’ve found evidence. There always is that potential.”

“The knife could hold some DNA, or even a latent fingerprint,” continues Adcock. “But just because someone’s DNA is there, doesn’t mean they’re guilty. DNA can get there in numerous ways.”

In addition, in a study published in the Journal of Forensic Sciences in 2014, it was found that “new information from witnesses or information from new witnesses” were the most prevalent reasons for case clearance.

Yet Simpson could not be charged again with these murders, as he has already been tried and acquitted – the double jeopardy legal standard applies – but this appears to make little difference to public interest in the case, with people still fascinated by every twist and turn, even 20 years later.

“This really was ‘the trial of the century,’ but that was largely down to the media,” says Adcock. “It was the start of court TV in the United States.”