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An Analysis of the O.J. Simpson Case Evidence and Forensic Techniques

Crime Scene

On June 12, 1994, investigators were called to 875 South Bundy Drive, a large house in a wealthy neighborhood of Brentwood, California, to follow up on a 911 call reporting a body sprawled out on the front walk of the house.  Upon arriving at 12:13 AM, investigators spotted a small large pool of blood that led up to a female body, later identified as Nicole Simpson, about fifteen feet away from the sidewalk.  Her back was aligned with the stairs behind her, and the left side of her face was pressed against the walkway.  She was fully dressed in a black dress, and her neck was cut from one ear to the other, nearly severing her head in the process.  Blood emanating from the wounds drenched her entire body. 

Shortly after this discovery, investigators discovered a male body, identified as Ronald Goldman, slightly to Simpson’s right, behind a bush.  The fully clothed body lay sprawled out on his right side, and blood covered his entire body.  He had multiple stab wounds over his body.  His eyes were open.  In between Goldman and Simpson lay a beeper, a knit cap, a set of keys, a bloody left-hand glove and a bloody white envelope.  Bloody footprints and blood drops led away from the bodies to the back of the property (Jones, 2008).


After securing the scene with 18 officers, the police force began to survey the area and take pictures of the general surroundings.

Investigators went to contact O.J. Simpson, Nicole Simpson’s ex-husband, at his house 2 miles away to ask him to collect his children.  There, they immediately noticed blood on the driver’s door of Simpson’s Bronco.  Fearing that Simpson had also become victim to murder because no one answering the phone, investigators climbed over the stone wall and unlocked the door to the property.  They came across a blood-stained right-handed glove on the walkway that looked similar to the bloody left-handed glove found at the crime scene, and blood drops near and in two cars, a Saab and a Bentley.  Further investigation of the Bronco nearby presented a multitude of blood stains around and inside the car.   Blood lead from the car to the front door of the house.  Soon a photographer was brought on scene to take pictures, and shortly after the blood spots and glove were confiscated without a warrant under the belief that the evidence was in plain view (Jones, 2008).

Meanwhile, back at the original crime scene, investigators had already begun collecting evidence.  Ten hours after they initially discovered the scene, medical examiners took the bodies away for autopsy (Ayres, 1994).  Meanwhile, investigators took pictures of footprints leading to the backyard and collected hairs from Goldman’s shirt (Jones, 2008).  They also found an abundance of evidence in the items littered near the two bodies; from there they collected a left-handed glove and a bloody envelope (Linder, 2006).   They also confiscated both the cap nearby and Goldman’s shirt, both of which contained hairs and fibers, and packaged them together in the same bag (Jones, 2008).  They swabbed blood from the various blood pools around the property, albeit with wet cotton swatches, and packaged them away in plastic bags before boarding them onto a hot truck (Thompson, 2008).   This blood would later be handled by a technician wearing gloves already dirtied by Simpson’s voluntarily given blood (Wang, 2001).  Some of the blood, however, was missed in the initial run-through, and was not collected until three weeks after the fact (Jones, 2008).

At O.J. Simpson’s house, even more evidence was found.  Investigators found blood spatters in the foyer and master bedroom, and confiscated a bloody pair of socks later discovered to be Nicole’s (Jones, 2008).  Importantly, the blood was not noted on the socks until approximately a week after the initial investigation (Thompson, 2008).  Investigators packaged these socks together rather than individually (transcript Linder).  A junior detective, Andrea Mazzola, collected the majority of the blood evidence without supervision, though captured on camera.  She was taped dropping several blood swabs and wiping tweezers with dirty hands (Jones, 2008).

The bloody glove found in the initial investigation was confiscated, and fibers lifted.  Inside the Bronco, investigators found multiple spatters of blood and a bloody footprint (Linden, 2006).

As suspicions began to grow about O.J. Simpson’s involvement in the murders, police requested a blood sample from him. Simpson complied, and Detective Phil Vannatter received the vial at 3:45 PM.  However, the vial would not make it into the hands of Dennis Fung, the evidence recorder, until 5:30 PM (Jones, 2008)

Description of Analytical Tests

Due to the enormous amount of blood evidence, the most important tests involved in the O.J. Simpson case were that of genetic fingerprinting.  In particular, the forensic laboratories used Restriction Fragment Length Polymorphism (RFLP) and Polymerase Chain Reaction (PCR).  RFLP, the more accurate of the tests, is typically used when there is more blood sample to work with, and is done by processing the DNA to produce autorads, which show the length of polymorphic fragments.  Investigators then examine the autorads to see if any of the fragments match, and, depending on the number of matches, determine the statistical likelihood of the DNA being the same as a suspect’s (Jones, 2008).  PCR, on the other hand, is a faster but less reliable process that is typically used when less blood is available.  It is accomplished by separating and then replicating the available DNA to the desired length (Kimball, 2008).

Genetic fingerprinting, however, wasn’t the only test run on the blood.  Technicians also performed toxicology tests, mainly to detect the degradation of blood and EDTA (Jones, 2008).

Shoeprint analysis was another important test run by investigators.  A shoeprint expert examined the shoeprints left behind at the scene to determine the size, class, wear and individual characteristics of that shoe.  Using this information, the expert looked for shoes of a similar make (Jones, 2008).

The last important sets of tests the forensics team ran were trace evidence tests, specifically hair and fiber analysis.  Hair analysis entails examining hairs under a microscope to determine whether they are human, and then comparing the known hair with a sample (Deedrick, 2000).  In O.J. Simpson’s case, investigators also analyzed the racial characteristics of each hair (Jones, 2008).  Fiber analysis is accomplished similarly under a microscope, examining the fiber to determine origin (natural or synthetic), color, length, diameter and other characteristics.  Neither test, however, can individualize evidence, and are usually only ancillary (Seiber, p. 157-163).

Lastly, an autopsy was done on the bodies to determine their exact cause of death and the weapon used.

Results of Analytical Tests

The results of the blood analyses were, at first glance, damning.  The largest of the bloodstains trailing from the bodies to the backyard of Nicole Simpson’s home was consistent with O.J. Simpson’s, with a likelihood of it being anyone else’s set at 1 in 170 million.  The other bloodstains in the area, all of which were smaller, were consistent with O.J. Simpson’s at a rate of 1 in 5,200.  Meanwhile, the blood in Simpson’s Ford Bronco tested consistently with a mix of O.J. Simpson, Nicole Simpson, and Ronald Goldman.  The glove found at Simpson’s home presented a similar profile—the blood resembled all three individuals’ blood.  The blood on the pair of socks found at Simpson’s home, however, was consistent solely with Nicole’s blood, possessing a genetic fingerprint that investigators argued could only present itself in a staggering 1 in 9.7 billion Caucasians (Jones, 2008).

Toxicology reports on the degradation of blood showed that Nicole’s blood on the socks was less degraded than blood retrieved directly from  her body during the autopsy.  Additionally, the blood on the gate, which had been collected 20 days later than all other evidence, hardly degraded at all despite being exposed to the weather (Jones, 2008).

Left without a shoe to work with it, the shoeprint analysis’s results was limited to determining the shoe manufacturer and size.  The FBI shoe expert involved claimed the shoe was a size 12 and of a rare Italian brand known as Bruno Magli, of which only approximately 300 was made in Simpson’s shoe size, 12 (transcript Bodziak).

According to hair analysis, the hairs collected off the cap and Goldman’s shirts were consistent were that of African-American  hair characteristics, particularly the characteristics of O.J. Simpson’s hair.  Hairs on the gloves, on the other hand, were consistent with Nicole Simpson and Ronald Goldman’s hair characteristics.  As for the fiber analysis, fibers found on Goldman’s shirt were similar to the fibers consisting of the socks found in O.J. Simpson’s house.  Additionally, fibers from the Ford Bronco were consistent with fibers from the glove found at O.J. Simpson’s home and the knit cap found at Nicole Simpson’s house (Jones, 2008).

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The autopsy, meanwhile, showed that both Nicole Simpson and Ronald Goldman had most likely been attacked with a knife that was approximately six inches long.  The examiner surmised, though he conceded he wasn’t absolutely positive, that the knife had been a single blade (Jones, 2008).

Conclusion and Analysis

From the data collected, it is most likely that O.J. Simpson committed the murder.  However, Simpson was not found guilty when tried in court, and this acquittal is generally attributed to the many mistakes made in the forensic part of the investigation (Jones, 2008).  While investigators acted correctly in many instances, such as taking photos and notes, cordoning off the scene, only having the appropriate professionals collect evidence and running the tests they did, too many of the processes were fatally flawed.  For instance, there were eighteen officers at the scene at one point.  Considering one of the most important aspects of an investigation is to keep contamination to a minimum (Seigel, pg 18), the more individuals at the scene, more likely evidence has been affected.  In this case, evidence was contaminated; an investigator placed a blanket over Nicole Simpson’s body to protect her from the eyes of the press (Jones, 2008).  Doing so immediately contaminated Nicole Simpson’s body and could have possibly affected evidence.  Basic CSI training dictates to never contaminate a scene (Siegel, pg 18).   The bodies were also not recovered by medical personnel for 10 hours, in which time precious evidence may very well have been lost.  Preferably, the bodies should have been taken away as soon as was suitable in the investigation.

The evidence collection process was the most flawed.  Blood was collected with wet swatches and then immediately put into a hot truck; placing blood samples in a moist, warm environment can cause rapid degradation and render the DNA unusable (Thompson, 2008).  The cap and Goldman’s shirt suffered a similar fate; the two were placed in a bag together, which provided ample opportunity for the trace evidence on both to mix.  O.J. Simpson’s blood was yet another possible victim of contamination.  It was collected by an investigator early in the afternoon, but instead of turning it in immediately, the investigator drove around with the vial in his pocket before finally turning it in several hours later.   This discrepancy of time would have given the investigator plenty of time to contaminate the blood (Thompson, 2008).  To top it off, some of the blood found was not collected until weeks after the fact, and appeared nowhere in the pictures taken at the time.  Had the blood been noticed on time, its validity in court wouldn’t have been so harshly challenged.  With no degradation even after sitting outside for several weeks, questions arose as to whether the evidence had been planted (Thompson, 2008).

The blood was further contaminated during DNA analysis, in which a technician ran tests using gloves that already had Simpson’s voluntarily given blood on them.  This provided a ripe opportunity for cross-contamination, and in turn false results about the DNA (Thompson, 2008). It also called into question whether the investigative personnel were well-trained; common sense would dictate to change gloves when testing different pieces of evidence.

This being said, O.J. Simpson was a perfect example of how improper collection and testing procedures can negatively affect a case.  Had investigators been better trained and less sloppy, O.J. Simpson would certainly be in bars.  However, this was not so, and O.J. walked away a free man with no justice served to those he killed.  It can be argued the only positive aspect of his legacy is the reminder to all forensic investigators the consequences that loom when a job is done poorly.

Reference List

"Simpson Case Has Errors, Coroner Says." New York Times 21 July 1994, A19 sec. New York Times. New York Times Company. Web. 31 July 2009. <>.

Deedrick, Douglas. “Hairs, Fibers, Crime, and Evidence.”  July 2000.  Federal Bureau of Investigation.  31 July 2009.

Jones, Thomas. “Analysis of the O.J. Simpson Murder Trial.” 2008.  TruTV. July 31, 2009.

Kimball, John. “The Polymerase Chain Reaction (PCR): Cloning DNA in the Test Tube.” 31 July 2009.   4 December 2008.

Linder, Douglas. “Famous American Trials: The O.J. Simpson Trial.”   2006.   University of Missouri-Kansas City School of Law.  31 July 2009. 

Siegel, Jay.  Forensic Science. Oxford, England: OneWorld.  2009.

“The State of California vs. Orenthal James Simpson”[transcript of testimony of William Bodziak].  19 June 1995.  University of Missouri-Kansas City School of Law.  31 July 2009.

“The State of California vs. Orenthal James Simpson”[transcript of testimony of Henry Lee].  19 June 1995.  University of Missouri-Kansas City School of Law.  31 July 2009. 

Thompson, William. “Proving the Case: The Science of DNA Evidence: DNA Evidence in the OJ Simpson Trial.” 30 December 2008.  Ramapo College of New Jersey.  31 July 2009,

Wang, Julie. “The Blood and DNA Evidence in the O.J. Simpson Trial.” 2001.  Forensic Biology. 31 July 2009.  


Akriti Mattu from Shimla, India on May 10, 2015:

Excellent analysis.

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