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might neeD A DNA EXPERT


In the January 3, 2012 blog article entitled, DNA Technology and Our Criminal Justice System, the key objective was to establish that forensic biology/DNA testing is by no means infallible. This is not to say that the technologies currently being used for evidence examination, body fluid identification, and DNA typing are anything but remarkable. However, challenges can emerge when the crime scene provides evidence that *seems* worthy of testing, but the scientific results simply fall short of providing any definitive answers. The case investigation and the legal proceedings become vastly problematic if forensic biology experts (either for the prosecution or the defense) allow themselves to SPECULATE beyond the scientific data. In the absence of definitive answers, one MUST NOT venture beyond the appropriate scientific interpretations.

As any investigation nears completion, the investigators, the crime lab, and the prosecution are obligated to provide their findings to the defense team. During 2003-2007, I was employed by the Indiana State Police as a Forensic Biologist. All of my 100+ case files included evidence item lists, detailed bench notes, meticulously prepared worksheets, microscopic exam observations, body fluid test results, DNA data, statistical calculations, and records of all of my communications with investigators, and prosecutors. Lastly, the results of each case were summarized within one, or a few brief reports.

The prosecution rarely asked me to provide any significant details beyond those few brief reports. On sixteen occasions, the prosecution required my testimony. I routinely took my place on the witness stand with my entire case file, a sizable stack of information-most of which neither the prosecution nor the defense attorney had ever seen.

As I look back on these events, I now find it quite baffling that both sides paid little more than sparse attention to the details outlined in my supporting case documents. The prosecutors at least had a reasonable degree of access to discussing various issues as the trial dates loomed ahead. Consequently, they occasionally made an effort to verbally explore a few details pertaining to the forensic analysis process. Outside of strict adherence to the discovery process, the defense counsel remained entirely in the dark.

Indiana State Police Forensic Biologists were instructed NOT to discuss any case issues with anyone other than the investigators or the prosecution. Through prior notification and approval, only formal requests for a deposition were allowed. Other than just a few depositions—over the course of four years at the crime lab—I was never called, e-mailed, or otherwise approached by any defense attorney—until I took the witness stand.

The vast majority of public defense attorneys, as well as private attorneys, have limited intimate knowledge regarding the inner workings of DNA analysis. Although most prosecutors are equally confused by the complexities of forensic biology, at least they have the luxury falling back on the expertise of the crime lab analysts. Where can the defense attorneys turn for clarification of complicated, troubling scientific issues? The cruel reality is that, in many circumstances, the mere, incidental reference to "DNA evidence", can cause the entire defense team to WITHER, FOLD UP THEIR TENTS, AND RETREAT. Such an unconditional surrender is particularly prevalent when the prosecution hints that “My DNA case looks pretty good.”

At this stage, readers might be realizing the potential gravity of the slanted criminal justice playing field—favoring the prosecution—and to the detriment of the accused. Note that the prosecution always has a ‘built in’ forensic DNA expert. Not just ANY expert, but a trained expert, working in a crime lab, with unlimited access to the criminal case evidence. In contrast, the defense counsel has, …well, …a license to practice law.

The marriage between criminal case law and forensic DNA technology is-on the surface-a perfect match. However this 'lopsided' forensic biology issue, can sometimes create an obstacle against the concept of a fair trial. Thus, the key question: WHAT SOLUTIONS ARE AVAILABLE TO ESTABLISH A LEVEL PLAYING FIELD IN FORENSIC BIOLOGY—to ensure fair trials for all citizens who have been accused?

First, let us assume that biological evidence WAS collected during a criminal case investigation. Let us also assume that either body fluids were identified, or DNA was successfully typed, ....or BOTH. Regardless of the prosecutor's intentions to use the reports and/or testimony from the crime lab analyst, the defense MUST obtain the reports-ASAP. The following scenario demonstrates WHY a sense of urgency is necessary:

Suppose that evidence has been collected from a homicide occurring at a residence. Let us also suppose that only ONE DNA profile was successfully typed as part of a multi-layered investigation. As time passes and hearings are conducted, the prosecution focuses on various aspects of the investigation, while devoting little or no attention to any DNA issues. The defense team might interpret this as a hint that the investigation must have failed to reveal any DNA results placing the defendant at the crime scene. The defense breathes a sigh of relief and moves on to other worries.

Much later, it becomes clear that the ONE DNA profile at the crime scene has originated from an unknown individual. Naturally, the prosecutor assumes that the unknown DNA type has nothing to do with the homicide. The genetic material-although present at the crime scene-was *probably* ‘incidental transfer DNA’ from an innocent friend, relative, neighbor, or perhaps the cable guy.

With these assumptions keeping the defendant wasting away in a local jail for untold months, the allegedly 'incidental' unknown DNA profile suddenly generates a 'hit' on a national DNA database. When the investigators check the identity of this 'hit', they are horrified to learn that this potential suspect has recently been incarcerated for a previous homicide. Upon visiting the prison and interrogating the prisoner, the man freely admits to participating in the '2nd' homicide. When asked about the defendant—who by the way, is STILL locked up in the local jail—the true perpetrator of the crime laughingly informs the investigators, “That guy wasn’t there. I don’t even know him.” A case resembling this scenario ACTUALLY OCCURRED.

Looking back at such a case, one has to wonder what would have happened if the crime lab had simply stored that one DNA evidence item—without ever testing it. What would have happened if the prosecution had decided NOT to introduce any biological/DNA evidence or insist upon any DNA testimony? The accused would most likely still be in prison.

When the defense team DOES receive an indication that there will be a forensic biology/DNA aspect of an impending case, the reports need to be promptly obtained and carefully reviewed. There are generally two types of reports released by forensic biologists at the law enforcement labs. One type is referred to as a Serology Report, or an Evidence Examination report. This is a summary of how the analyst examined each evidence item and the body fluids that are either presumed or confirmed to be present.

A subsequent report might summarize the results of DNA testing. Note that some crime labs direct their analysts to pool all of this information into ONE report—summarizing BOTH the evidence examination—as well as the DNA data. Also be aware that supplemental reports are often released—addressing the analysis of additional items that the investigation team decided to examine at a subsequent date.

In the event that a person on the defense team recognizes questionable issues within the reports, a DNA expert should be utilized for a thorough case evaluation. Note that Spence Forensic Resources provides excellent expertise and support relevant to the DISCOVERY PROCESS AND TRIAL PREPARATION

The most notable ‘red flag’ issues in the crime lab reports can be varied. When the word “mixture” is mentioned anywhere on a DNA report, outside consultation is a MUST. I have noticed that some crime lab reporting guidelines actually choose to avoid the term “mixture” in their reports. Instead, the reports generically refer to the “DNA profile” and refer to a major component, minor components, minor alleles, etc. When a trained a forensic DNA consultant comes across such terms as “major” and “minor” it is clear that a DNA mixture has been observed. However, mentioning ‘major/minor’—without clarification for non-scientist readers—hints at an intentional effort to skirt the issue—that multiple DNA profiles have been found upon an isolated surface.

Although DNA reports typically list each item, and will attempt to clarify WHO left DNA on each item, only the analyst bench notes can clarify PRECISELY WHERE the tested material was taken from the evidence. Note that the evidence item might be as small as a paper clip, or as large as a pick-up truck.

Only the DNA quantification data—which is typically found among the supporting documents—can reveal precisely HOW MUCH (or how little) DNA was recovered. Note that I have NEVER seen DNA quantitative data in a DNA report. Sometimes, "HOW MUCH?" is the paramount question.

As my readers may have already heard before (and I will emphasize it countless more times): Be it ever so powerful, DNA technology cannot tell us WHEN DNA was deposited at a specific location. DNA testing also cannot tell us HOW the DNA came to be at that location.

If any DNA report includes the phrase “touch DNA”, the analyst and the crime lab’s Quality Assurance Manager should both be immediately incarcerated. Use of such glaring, scientific misnomers in a report, or on the witness stand, is an appalling breach of professional ethics. 

Until new forensic tools are discovered, today’s technology is incapable of confirming that DNA is present because the sampling site HAS BEEN TOUCHED, or HAS NOT BEEN TOUCHED. Consequently, how can it be scientifically accurate to testify to the accuracy of the phrase “touch DNA” when there is no validated test confirming that touching ever occurred? Competent scientists will resist falling into the trap of prejudicial misnomers and mis-characterization of the results. Acceptable alternative phrases include LOW COPY NUMBER DNA, or TRACE DNA. These terms indicate tiny quantities of DNA, but imply NOTHING about how the DNA came to be at a specific location. In the near future, I will devote an entire article to this topic: Criminal Trial Controversies: DNA Transfer Events

The individual assigned by the defense to initially assess a forensic DNA lab report, must take into consideration the context of the case circumstances. DNA mixtures, tiny deposits of DNA—from either a confirmed body fluid, or some undetermined cell type—should all be viewed as they relate to the statements from the defendant and various witnesses.

Just one example: Perhaps a witness saw a carjacker attempt to use a rag to wipe fingerprints from the steering wheel moments before exiting the vehicle and fleeing the scene. If this is correct, why is the prosecutor convinced that the DNA mixture detected on the steering wheel is providing enormous revelations about the crime? Perhaps the rag in question was recovered by a CSI, but was—for some reason—never tested for DNA. How do we know that the defendant’s DNA was not deposited onto the steering wheel, ….from the rag? Does anybody ever collect a ‘substrate control’? A future article will center on the importance of SUBSTRATE CONTROLS.

Such issues and observations—which will vary dramatically from case to case—may give defense counsel a powerful cause for filing a motion to bring a DNA expert onto the defense team. Perhaps it might also become necessary for the defense team to craft an outsource DNA testing strategy. Every criminal case is different.

The next article will be entitled:

Criminal Trial Controversies: DNA Transfer Events

Michael J. Spence, Ph.D.

December 29, 2011


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