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Unreliable or Improper Forensic Science

Since the late 1980s, DNA analysis has helped identify the guilty and exonerate the innocent nationwide. While DNA testing was developed through extensive scientific research at top academic centers, many other forensic techniques – such as hair microscopy, bite mark comparisons, firearm tool mark analysis and shoe print comparisons – have never been subjected to rigorous scientific evaluation. Meanwhile, forensics techniques that have been properly validated – such as serology, commonly known as blood typing – are sometimes improperly conducted or inaccurately conveyed in trial testimony. In some cases, forensic analysts have fabricated results or engaged in other misconduct.

Forensic Science Misconduct

Because forensic science results can mean the difference between life and death in many cases, fraud and other types of misconduct in the field are particularly troubling. False testimony, exaggerated statistics and laboratory fraud have led to wrongful conviction in several states.

Since forensic evidence is offered by "experts," jurors routinely give it much more weight than other evidence. But when misconduct occurs, the weight is misplaced. In some instances, labs or their personnel have allied themselves with police and prosecutors, rather than prioritizing the search for truth. Other times, criminalists lacking the requisite knowledge have embellished findings and eluded detection because judges and juries lacked background in the relevant sciences, themselves.

In some cases, critical evidence has been consumed or destroyed, so that re-testing to uncover misconduct has proven impossible. Evidence in these cases can never be tested again, preventing the truth from being revealed.

One weak link
The identification, collection, testing, storage, handling and reporting of any piece of forensic evidence involves a number of people. Evidence can be deliberately or accidentally mishandled at any stage of this process.

The risk of misconduct starts at the crime scene, where evidence can be planted, destroyed or mishandled. Evidence is later sent to a forensic lab or independent contractor, where it can be contaminated, poorly tested, consumed unnecessarily or mislabeled. Then, in the reporting of test results, technicians and their superiors sometimes have misrepresented their findings. DNA exonerations have even revealed instances of "drylabbing" evidence – reporting results when no test was actually performed.

All over the map
The Innocence Project has seen forensic misconduct by scientists, experts and prosecutors lead to wrongful conviction in many states. The following are among the more notorious:

•  A former director of the West Virginia state crime lab, Fred Zain, testified for the prosecution in 12 states over his career, including dozens of cases in West Virginia and Texas. DNA exonerations and new evidence in other cases have shown that Zain fabricated results, lied on the stand about results and willfully omitted evidence from his reports.

•  Pamela Fish, a Chicago lab technician, testified for the prosecution about false matches and suspicious results in the trials of at least eight defendants who were convicted, then proven innocent years later by DNA testing.

•  A two-year investigation of the Houston crime lab, completed in 2007, showed that evidence in that lab was mishandled and results were misreported.

Ending forensic fraud
The Innocence Project has uncovered these abuses since 1992 and has developed recommendations for forensic labs, law enforcement agencies and courts to ensure that forensic science misconduct is prevented whenever possible. The Innocence Project calls for states to impose standards on the preservation and handling of evidence. When exonerations suggest that an analyst engaged in misconduct or that a facility lacked proper procedures or oversight, the Innocence Project advocates for independent audits of their work in other cases that may have also resulted in wrongful convictions.

Visit our Fix The System: Crime Lab Oversight page for more information.


Featured Case: George Rodriguez

George Rodriguez was exonerated in 2005 after serving 17 years for a sexual assault he didn't commit. Rodriguez's case helped to reveal a pattern of error and fraud in the Houston Police Department Crime Lab that is still being investigated and corrected today. In Rodriguez's case, lab director Jim Bolding testified that a hair found in the victim's underwear could have belonged to Rodriguez. He also testified that blood type evidence showed that Rodriguez – and not a co-defendant – could have deposited biological fluids. This was false – later tests showed that the co-defendant could have been a contributor. DNA testing also showed that the hair used against Rodriguez could not have been his. Audits of the Houston lab since Rodriguez's exoneration have revealed a wide range of misconduct.

Click here to read Rodriguez's full profile.