From DNA to the murder weapon, the show uncovers evidence that was overlooked during trial

More than two decades after O.J. Simpson was acquitted of murdering his wife Nicole Brown Simpson and her friend Ronald Goldman, the case still captivates crime watchers.

Although the former football star was found not guilty, a jury found him civilly responsible for the victims’ wrongful death. He was ordered to pay $33.5 million to surviving family members.

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A new docuseries advances the theories that Simpson, now 69, might not have committed the murders or that he had help carrying them out.

• PEOPLE’s special edition True Crime Stories: Cases that Shocked America is out now.

Investigation Discovery’s six-part series, Is O.J. Innocent? The Missing Evidence, explores new theories and never-before-seen evidence in the high-profile case.

In the exclusive promo above, the show alleges that the blood evidence is inconsistent with the theory that Simpson acting alone. Among other evidence, the series raises the possibility that there were two sets of bloody footprints and blood in the passenger seat of Simpson’s infamous white Ford Bronco.

• Want to keep up with the latest crime coverage? Click here to get breaking crime news, ongoing trial coverage and details of intriguing unsolved cases in the True Crime Newsletter.

Additionally, one expert displays a knife he believes was used in the murders. Despite numerous searches, investigators have never been able to find the murder weapon.