Oct. 28, 2013
How would the forensics case against O.J. Simpson stack up today? A former supervisor of NYPD’s Forensic Investigations Division takes a look.
by John Paolucci
The murders of Nicole Brown Simpson and Ron Goldman initiated an investigation and an eight month trial that had all the ingredients a news story needs to catch the public’s eye such as scandals involving sex and racism, celebrity, wealth and murder. The events did everything from boosting white Ford Bronco sales to educating the public on homicide investigations, forensic evidence, and those three letters that have since become quite commonplace in our vocabularies today: DNA. The consecutive days spent on the witness stand by the forensic scientists who performed the analyses and comparisons for the “People of the State of California,” scientists from private laboratories where certain analyses were “outsourced,” and experts hired to refute their findings and plant seeds of reasonable doubt provided the jury and the public with a crash course in forensic evidence and DNA.
I had been asked to provide a reporter friend with an interpretation and opinion of the forensic evidence in the O.J. case and in doing so became aware of how significantly our practices and technology has evolved that I was inspired to write this article. This is by no means a comprehensive account of all forensic evidence introduced at the trial; the purpose is to highlight the stark differences between what transpired with the LAPD in 1994 and the ensuing trial in 1995, and how the same case would have been handled during my tenure in the NYPD’s Forensic Investigations Division.
- 1. Let us begin by delineating the differences between the Simpson jury and today’s jurors who have been contaminated by the “CSI Effect”
1995: The task at hand for both the prosecution and the defense was “Education” –They had to educate the jury about DNA’s significance as a biometric identifier. The jury needed to understand and accept that a DNA profile developed from a crime scene sample can have the likelihood of one in so many million (over a trillion today) that it was deposited by a person other than the defendant. It was a difficult endeavor for the prosecution to win the jury’s confidence in this scientific phenomenon. The defense also needed to have the jury understand the science behind how a genetic profile is developed in order to present their case as to how the results were skewed by mishandling of the evidence and open the door to the possibility that Simpson’s DNA profile could have been “planted” by the Detectives.
2013: Today’s jurors have a less than realistic idea of how DNA collection and analysis works so the task would be “Nullification” – For modern day jurors, DNA is readily accepted as the holy grail of forensic evidence, and expected to be a part of every criminal investigation. However, myths instilled by crime dramas about a clean profile being developed from just about any substrate, instant analysis turnaround time, and databases replete with matching suspects and convicted offenders (complete with photos) have to be dispelled. It is not uncommon for items such as firearms to have insufficient quantities of genetic material on them to create a DNA profile, though this never happens on TV.
- 2. Let’s next examine what is called “Reference DNA” Reference DNA is collected from a suspect or a victim for the purpose of making comparisons to DNA profiles developed from evidence collected at a crime scene. It is also called a DNA “Exemplar.”
1994: A vial of blood was required to be collected from Simpson in order to develop his DNA profile. Not only does this indicate the massive amount of genetic material needed to develop a profile in 1994, but it also opens the door for Simpson’s defense team to make allegations that some of the blood collected from Simpson was planted at the crime scene. The defense also introduced a volume discrepancy with the vial of Simpson’s blood, claiming the reference blood was missing approximately 1.5 ml from the time of collection to the time it was received in the laboratory. Since the biological material needed to develop Simpson’s DNA profile was blood, it would have been possible for his blood to either be planted at the scene or mishandled by laboratory personnel causing cross contamination and the appearance that Simpson’s blood was found on evidence collected at the crime scene.
2013: Now that higher sensitivity testing is available, reference DNA would be collected by means of a buccal swab, meaning skin cells collected by swabbing the oral cavity. Buccal swab collection kits are collected, packaged, sealed and signed in the defendant/suspect’s presence. Even if a kit could be opened and the swab removed, how would you go about taking skin cells collected on the buccal swab and plant them at a crime scene? It is a more efficient means of collecting reference DNA that can be performed by police personnel at just about any location, thanks to improvements in the sensitivity of testing. If Simpson’s reference DNA was collected on a buccal swab there would have been less room for allegations of corruption and incompetence – by the defense team.
- 3. Another issue that caused confusion in the jury box was “Substrate Control” samples. In the earlier stages of DNA testing, substrate control swabs were routinely collected in order to identify any substrate specific conditions that could affect DNA analysis results, i.e., when blood was swabbed from the sidewalk, was there something on the sidewalk that could have affected the DNA testing?
1994: Substrate control samples were collected right near the stain or area from which the crime scene investigator is taking his evidence swab from so the analyst could test the substrate control sample and compare the results to the results from the swab that collected the blood. The prosecution attempted to introduce substrate control samples to impeach defense claims that Simpson’s reference DNA had contaminated blood evidence from Bundy residence in the laboratory. The Defense showed that substrate control samples were not examined in parallel with the Bundy crime scene blood swabs, demonstrating another violation of laboratory protocol.
2013: Advances in DNA technology no longer require the collection of substrate control samples (that practice ended around the year 2006 in New York City).
- 4. If you’re lucky enough to have a few jurors still following all of this, the introduction of “Mixtures” could be enough to lose them. Since some of the blood from both the victims and the suspect was commingled, mixtures of their DNA profiles resulted from many of the tests performed.
1995: Testimony about mixed profiles further confounded the DNA science for the jury, making them more prone to dismiss DNA evidence from mixtures rather than decrypt the expert witnesses’ explanations.Nebulous language such as “cannot be excluded” was used (still is) to describe the nexus between a reference samples and a mixture. “Cannot be excluded” means that there is enough information available from the profile developed to possibly be the same profile as the reference sample, though it cannot be conclusively determined that the profile actually is that person.
2013: Higher sensitivity testing allows mixtures to be more decipherable, making it easier to identify donors from comparisons to reference samples. Also, “Y STR” DNA typing of the Y chromosome can be performed to differentiate male donors and isolate the males genetic code on the Y chromosome when mixed with a female, to make a positive identification of the male DNA within a mixture. Reference samples have to be tested again or “re-typed” using Y STR typing, which in this case would have had a significant impact.
- 5. The defense highlighted sloppy police work that could have resulted in cross contamination or “Scene to Scene” evidence transfers:
1994: Personnel from the Bundy crime scene were traveling back and forth to the Rockingham (Simpson’s house) crime scene. Video and photos from the Bundy crime scene portrayed a lack of coordination and excessive personnel and even members of the media entering the crime scene. Failure to control police personnel causes investigators to be distracted and this confusion could be responsible for the crime scene technician to miss significant evidence such as a bloody fingerprint from the rear gate of the Bundy crime scene that was never collected.
2013: Strict protocols on Personal Protective Equipment (PPE) such as the wearing of disposable coveralls are emphasized in training and routinely practiced. Each scene would have a team of two investigators, with the “catching” team member doing all the collecting and photographing of physical evidence to be collected so that the same evidence collectors are not bringing evidence from one scene to the other.
- 6. Modern technology would have provided more conclusive results with the hair evidence from Bundy crime scene:
1994: Hair collected from Goldman’s shirt and a knit cap recovered at the Bundy crime scene was compared to defendant’s hair; Microscopic comparisons of hairs cannot conclusively link a known standard to a questioned sample. The best result is that the two are “microscopically similar.”
2013: If the questioned hair from the crime scene still has some of its root on it, the DNA testing of the root material could be performed and compared to the reference samples. Also, mitochondrial DNA analysis of the crime scene hair samples could positively identify or exculpate the defendant. It would have been very difficult for the defense to explain how a hair that has proven to be Simpson’s was on Goldman’s shirt! DNA testing of the epithelial cells on the knit cap would have not been overlooked and would certainly have a higher probative value than the hair collected from the knit cap.
In conclusion, there is no way to state with any certainty how a jury will vote, especially a jury that has been in the same courtroom for eight months. I would say that with the public having a better understanding of DNA and other forensic evidence and the clarity that today’s technology can provide, a modern day jury would be more likely to understand and give appropriate credence to the abundance of forensic evidence that was collected in the case against O.J. Simpson. It would certainly outweigh a blood soaked leather glove that dried up in an evidence locker and could not easily slide onto the defendant’s gloved hand.
--John Paolucci is a retired detective sergeant from NYPD who worked his last eight years in the Forensic Investigations Division, four of them as a Crime Scene Unit supervisor. He was the first ever to command the OCME Liaison Unit where he vetted and managed all DNA evidence collected in New York City. He developed a strong alliance between the Office of Chief Medical Examiner (OCME) and NYPD and was instrumental in developing new protocols and procedures regarding forensic evidence collection and documentation. He also worked as a Narcotics Undercover and Patrol Officer in the Housing Projects of the South Bronx. He is currently the president of Forensics 4 Real Inc., and trains students and law enforcement in forensic evidence and crime scene investigations. He also provides consultations with movie and television writers, directors and developers working on real crime shows and dramas. As President of Forensics 4 Real Inc. he has provided forensic support to private investigations and traveled to Paraguay where he exhumed a body for the collection of DNA evidence to assist in an insurance fraud case. His website is: www.forensics4real.com.