What the Knife on Found OJ Simpson’s Old Property Might Mean – A Short Explainer

A forensic expert breaks down the hurdles in tying knife to infamous 1994 murders

More than 20 years after the murders of Nicole Brown Simpson and Ron Goldman, the case took an unexpected turn on Friday, as the Los Angeles Police Department announced that it had obtained and is testing a knife apparently found buried on the former Brentwood estate of O.J. Simpson.

The discovery is potentially significant; the murder weapon was never found, but during the civil trial against Simpson, county coroner Lakshmanan Sathyavagiswaran testified that the weapon was likely a single-edged knife. Simpson was acquitted of criminal charges for the crimes in a high-profile 1995 trial.

While the discovery of the knife has just been announced and the police still have to conduct their investigation, Gary A. Rini, an independent forensic science consultant with than 40 years of experience, told TheWrap on Friday that there’s a “whole set of problems” in trying to connect the knife to the notorious murders.

First, there’s the chain of custody of the knife, which was reportedly found buried on the property by a construction worker back in the 1990s, who turned it over to an off-duty police officer, who then kept it for more than a decade before turning it over to the LAPD as evidence within the last month.

“Why would a detective have it in his drawer for so long? This is one of the kinds of issues that plagued the original trial; they didn’t have the proper chain of custody of some of the evidence,” Rini said.

The circumstances could offer an opportunity for defense attorneys to exclude the weapon as evidence. “Attacks could be made if they brought [the knife] forward,” Rini added. “Whether or not that blood was placed there after the act. If the detective had that knife in his possession, is it possible that he also had some sample of Goldman’s or [Nicole Brown Simpson’s] blood that he could have transferred on there? There’s a whole set of problems if they ever tried to use it as a piece of evidence in a court of law.”

Rini also noted that under the laws of double jeopardy Simpson himself can’t be prosecuted again for crimes for which he has already been tried and acquitted — even if the weapon holds DNA evidence that further implicates him. However, Rini said prosecutors could try to find a way to try him in federal court.

The passage of time and the condition in which the knife was found also create hurdles, Rini said.

“Environmental factors will play an important part,” Rini said. “There are locations on a knife that are particularly useful in situations like that.” He cited the hilt of a knife, where the blade enters the handle. If it’s a folding knife and the knife was folded, that “would also offer some minimal level of protection of any possible blood stains that were on there,” Rini said.

In some ways, though, the passage of time is beneficial to the investigation.

“There’s a lot of development of DNA testing since the time of the O.J. trial that enables them to take minute amounts of stains and multiply it to a point where they can test it,” Rini said.

“At the end of the day, is it possible for them to test it? Yes,” Rini said. “Is it possible for them to possibly get some positive results? I suppose it is.”