The physical evidence in the O.J. Simpson case formed a forensic trail across three locations: the Bundy Drive murder scene, Simpson’s Rockingham estate, and his white Ford Bronco. Blood drops matched by DNA, a pair of extra-large leather gloves, bloody size-12 shoe prints, hairs consistent with Simpson’s, and blue-black fibers linked him to the June 12, 1994, stabbing deaths of Nicole Brown Simpson and Ronald Goldman. A criminal jury acquitted him on October 3, 1995, after fewer than four hours of deliberation. A civil jury later found him liable. What follows is what the evidence actually showed, and why the two juries reached different answers.
Blood and DNA Linking Simpson to the Scene
Detective Philip Vannatter testified that he saw five blood drops running alongside bloody shoe prints that led away from the victims on the Bundy Drive walkway. The drops appeared unrelated to Nicole Brown Simpson or Ronald Goldman, suggesting the killer was bleeding, likely from the left hand.1Famous Trials. Testimony of Philip Vannatter Additional blood turned up on the property’s rear gate, though that sample was not collected until several weeks after the initial processing.
Two DNA techniques were used on the evidence. Restriction Fragment Length Polymorphism (RFLP) was the more powerful test but required a minimum amount of intact DNA. Polymerase Chain Reaction (PCR) copied and amplified smaller or degraded samples so they could be profiled. Defense expert John Gerdes called the PCR testing “inadequately controlled” for crime scene work but said he had no issue with the RFLP results.2UPI. DA: New DNA Tests in O.J. Case
The match probabilities were extraordinary. Robin Cotton, director of the Cellmark Diagnostics DNA laboratory, testified that blood found near the victims at Bundy could have come from only one in 170 million people, and it matched Simpson’s profile. Blood on a sock recovered from Simpson’s bedroom matched Nicole Brown Simpson’s DNA at a frequency of one in at least 6.8 billion, a figure larger than the world’s population at the time.
The Aris Isotoner Gloves
Two extra-large Aris Isotoner leather gloves became the case’s most recognizable evidence. One was found near the victims at Bundy Drive; its mate turned up on the grounds of Simpson’s Rockingham estate. Former Aris Isotoner executive Richard Rubin identified both as the left and right hands of style 70263 and testified that only Bloomingdale’s carried that model.3Famous Trials. Testimony of Richard Rubin
On June 15, 1995, Simpson tried the gloves on in front of the jury. He grimaced, struggled to pull them over his hands, and told jurors they were “too tight.” The prosecution later argued the leather had shrunk after being soaked in blood and subjected to repeated forensic testing. In closing, defense attorney Johnnie Cochran fixed the image in the jury’s mind: “Remember these words: if it doesn’t fit, you must acquit.”
The Socks and the Planting Theory
A pair of dark dress socks recovered from Simpson’s bedroom floor carried blood that DNA testing matched to Nicole Brown Simpson. Prosecution witnesses acknowledged the stains were not noticed at the time of collection and were only observed months later. The defense argued the blood had been planted from reference samples held in the crime laboratory.
That theory hinged on EDTA, a preservative added to blood collection tubes to prevent clotting. If blood on the socks or the Bundy rear gate contained EDTA at levels consistent with a lab tube, it would suggest the stains came from stored samples rather than fresh contact. FBI examiner Roger Martz tested the evidence using liquid chromatography and mass spectrometry and reported that EDTA was present in the preserved reference blood but was not identified in the bloodstains on the rear gate swab or the socks.4U.S. Department of Justice Office of the Inspector General. A Review of FBI Laboratory Practices The defense challenged his methodology, but his findings stood as the prosecution’s primary rebuttal to the planting allegation.
Hair, Fiber, and Shoe Print Evidence
A dark blue knit cap found near Goldman’s body contained 12 hairs that FBI expert Douglas Deedrick testified matched Simpson’s hair characteristics. Hairs with the same features appeared on Goldman’s shirt and on the Rockingham glove. Blue-black cotton fibers were found on Goldman’s shirt, the Rockingham glove, and the socks in Simpson’s bedroom. Deedrick also identified rose-beige carpet fibers on the knit cap and glove that he testified “could have originated” from the carpet inside Simpson’s Ford Bronco, noting the fiber’s cross-section was unusual and unlike anything he had previously seen in other vehicles.5UPI. Bronco Fibers Resemble Those on Evidence
The bloody footprints leading away from the victims were identified by FBI Special Agent William Bodziak as size 12 Bruno Magli shoes in the “Lorenzo” style, with a distinctive Silga rubber sole. Only 299 pairs of size 12 Lorenzos had been distributed across roughly 40 stores in the entire United States, with most stores receiving just one pair at a time.6Famous Trials. Testimony of William Bodziak The shoes retailed for $160. Bodziak eliminated the footwear of every officer who had walked through the scene and concluded he “could include [Simpson] as a candidate for possibly having worn those shoes.” Simpson denied ever owning Bruno Magli shoes.
The Bronco and the Rockingham Blood Trail
Simpson’s white Ford Bronco produced its own set of blood evidence. Investigators found blood on the door handle, and luminol testing revealed additional traces inside the cabin. DNA profiles from the interior matched both victims and Simpson, placing biological material from all three in a single confined space.
At Rockingham, investigators documented blood drops running from the parked Bronco to the front door and additional blood inside the foyer. DNA testing on those samples was consistent with Simpson’s own profile.1Famous Trials. Testimony of Philip Vannatter The prosecution’s story was straightforward: Simpson returned home after the murders, bleeding from a cut on his left hand, and tracked blood from the vehicle into the house.
Why the Evidence Didn’t Convict
The defense did not attack DNA testing itself. It attacked how the LAPD collected and handled the evidence. Barry Scheck later summed the strategy up this way: “We had a 21st century technology and 19th century evidence collection methods.”
LAPD criminalist Dennis Fung admitted to several collection errors under cross-examination. He acknowledged missing blood drops on a fence near the victims during initial processing and returning weeks later to collect them. He conceded he had not worn rubber gloves when handling some evidence. Those admissions fed a narrative that sloppy technique had either contaminated samples or created chances for tampering.
The defense also pressed on roughly 1.5 milliliters of blood missing from Simpson’s reference vial. The nurse who drew the sample estimated he had taken about 8 milliliters; the LAPD could account for only 6. Detective Vannatter carried the vial around for several hours before booking it into the chain of custody. The defense argued the unaccounted blood had been used to plant evidence. Because no documentation recorded exactly how much blood was originally drawn, the prosecution could not fully neutralize the allegation.
The jury deliberated for fewer than four hours before acquitting Simpson on October 3, 1995. The defense had reframed the question from “does the DNA match?” to “can you trust the people who collected it?”
What the Civil Trial Added
The Goldman and Brown families filed a wrongful death civil suit, which operated under a lower standard of proof: a preponderance of the evidence rather than proof beyond a reasonable doubt. The civil trial also introduced evidence absent from the criminal case. A photograph taken by freelance photographer E.J. Flammer showed Simpson wearing Bruno Magli shoes at a Buffalo Bills football game on September 26, 1993, roughly nine months before the murders. That directly contradicted Simpson’s deposition testimony that he never owned such shoes. Bodziak matched 18 features in the photograph to the Bruno Magli Lorenzo style. In February 1997, the civil jury found Simpson liable and awarded $33.5 million in damages.
How the Case Changed Forensic Practice
Before 1995, DNA testing was a relatively obscure courtroom tool that most jurors and many attorneys barely understood. The Simpson trial made DNA profiling a household concept and forced law enforcement agencies to confront serious deficiencies in how they collected and processed biological evidence.
The concrete legacy was a push toward mandatory laboratory accreditation. The FBI’s National DNA Index System now requires participating forensic laboratories to meet Quality Assurance Standards and obtain accreditation, with organizations like ANAB operating under a memorandum of understanding with the FBI to assess compliance. Federal Rule of Evidence 702, which governs expert testimony, was amended in December 2023 to clarify the trial court’s gatekeeping role: a judge must determine by a preponderance of the evidence that expert testimony is based on sufficient facts, reliable methods, and a reliable application of those methods to the case.7National Institute of Justice. Law 101: Legal Guide for the Forensic Expert
The Simpson case did not discredit DNA evidence. It exposed the gap between what the science could prove and what investigators were equipped to deliver, and it pushed the system to close that gap.