Forensics at the OJ Simpson Trial

So…What Went Wrong?

Evidence Collection
From the beginning, there were issues involving evidence collection. An important bloody fingerprint located on the gateway at Nicole Brown’s house was not properly collected and entered into the chain of custody when it was first located. Although it was documented in his notes by Detective Mark Fuhrman, one of the first to arrive on the scene, no further action was taken to secure it.

The detectives who took over Fuhrman’s shift apparently were never aware of the print and eventually, it was lost or destroyed without ever being collected. Other items of evidence were also never logged or entered into the chain of custody, which gave the impression that sloppy forensic collection had been carried out at the scene.

The prosecution had expert witnesses who testified that the evidence was often mishandled. Photos were taken of critical evidence without scales in them to aid in measurement taking. Items were photographed without being labeled and logged, making it difficult, if not impossible, to link the photos to any specific area of the scene. Separate pieces of evidence were bagged together instead of separately, causing cross-contamination. Wet items were also packaged before allowing them to dry, causing critical changes in evidence. Police even used a blanket that came from inside the house to cover Nicole Brown’s body, contaminating the body and anything surrounding it. Beyond poor evidence collection techniques, sloppy maneuvering at the scene caused more bloody shoe prints to be left behind by LAPD than by the perpetrator.

Securing the Evidence
Throughout the investigation, there were issues with how evidence was secured. There was about 1.5 mL of O.J. Simpson’s blood assumed missing from a vial of evidence. The LAPD could not counter the idea of “lost blood” because there was no documentation of how much reference blood was taken from Simpson as evidence. The person who drew the blood could only guess he had taken 8 mL; only 6 mL could be accounted for by the LAPD.

To add to the problem, the blood was not immediately turned over as evidence but was carried around for several hours before it was entered into the chain of custody, allowing for speculation of when and how the 1.5 mL of blood may have disappeared.

The security of LAPD storage and labs was also brought under scrutiny when it was discovered that some pieces of evidence had been accessed and altered by unauthorized personnel. Simpson’s Bronco was entered at least twice by unauthorized personnel while in the impound yard; Nicole Simpson’s mother’s glasses had a lens go missing while it was in the LAPD facility.

A Question of Planted Evidence
Not only were there many claims that the evidence was mishandled in the police lab, but there were also claims that evidence was planted at the crime scene. Because the police department did not have proper collection documents regarding Simpson’s blood, it was argued that the police planted Simpson’s missing blood on critical evidence and in critical areas of the murder scene.
The defense team stated that EDTA was found in the samples of blood that were collected at the crime scene. EDTA is a blood fixer (anticoagulant) used in labs and mixed with collected blood. If evidence with Simpson’s blood showed traces of EDTA, the defense claimed, then that blood had to have come from the lab, which meant that it was planted.

However, EDTA is also a chemical found naturally in human blood and chemicals such as paint. At the time, tests were not readily available to differentiate between natural and contaminant EDTA or the differences in the level of EDTA in blood. Some believe that the positive EDTA results may have been due to contamination of the equipment used to run the tests.

A Question of Character
Detective Fuhrman was discredited by the prosecution when he was alleged to be a racist and accused of planting evidence. When asked if he had falsified police reports or planted evidence in the Simpson case, he invoked his 5th Amendment rights against self-incrimination. Fuhrman was accused of planting critical evidence, contaminating it with Simpson’s blood, and falsifying police records. In Fuhrman’s book, he stated that at one point he was even accused of killing Nicole Brown and Ron Goldman himself. This put anything he touched in the investigation under scrutiny.

Understanding Forensic Science
A major hurdle that the prosecution team failed to overcome was the lack of knowledge and understanding regarding forensics, specifically the relatively new science of DNA. The jurors agreed that the DNA testimony was difficult to appreciate since expert witnesses were not able to put their evidence in terms that the jury could understand.

This inability to understand key evidence made the evidence essentially useless; even some seasoned lawyers found the scientific testimonies to be incomprehensible. It is reported that the DNA evidence showed that the chance that some of the blood found near the bodies came from anyone but Simpson was 1 in 170 million. The chance that blood found on Simpson’s sock could be from someone other than Nicole Brown was 1 in 21 billion. Blood samples found inside of Simpson’s Bronco, which was discovered outside Simpson’s home the next day, were equally matched to Simpson and both victims. Such evidence should have resulted in an open and shut case by today’s standards, but was not made clear enough to understand at the time.

What happened in the trial of O.J. Simpson that led to his acquittal?
The role of the jury is to listen to both sides of the case (prosecutor and defense). The jurors have to unanimously decide guilt or innocence. Whatever the outcome, the jurors must feel that their decision is beyond reasonable doubt. This was particularly difficult to achieve in this case. Going in, the public were already influenced by Simpson’s likeability and star power as a pro football player and beloved celebrity. Changing that initial perception was going to be tough. While the abundance of evidence certainly provided more than enough to do so, the doubts cast by the sloppy police work were enough of a window. Additionally, some jurors have since admitted that the verdict was retribution for the acquittal of white police officers in the beating of Rodney King in 1992.

More information about the O.J. Simpson case can be found here.