Understanding common causes of issues with forensic evidence in Texas

Forensic evidence may be inaccurate due to errors or misconduct by analysts, the use of unproven methods and improper interpretation of this evidence.

In criminal justice proceedings, forensic evidence is often seen as an objective and highly reliable form of evidence. However, research and exoneration records reveal that this is not always the case. Shockingly, according to the National Registry of Exonerations, misleading or false forensic evidence has been identified as a factor in 126 out of 286 cases in which people in Texas were wrongfully convicted and later exonerated.

Several factors can increase the likelihood of innocent people being convicted on the basis of questionable forensic evidence. It is imperative for juries and people facing criminal charges in Houston to be aware of these risk factors.

Unreliable methods

Contrary to what most people may believe, many forensic techniques and forms of evidence have never been scientifically established as reliable. For example, a recent report from the President's Council of Advisors on Science and Technology states that the following widely used forms of evidence have yet to be validated through independent testing and research:

  • Fingerprint analysis
  • Bite-mark comparisons
  • Firearm and tool mark analysis

Even esteemed forensic techniques, such as DNA analysis, are not infallible. For example, in cases that involve multiple DNA samples, the likelihood of a correct identification is much lower.

Overstatement of reliability

Problematically, questionable forensic evidence may frequently be presented in trial as accurate or incontrovertible. This is true even in high-stakes cases that involve serious felony charges, such as rape or murder. In one high-profile example, the FBI admitted in 2015 that its analysts gave flawed testimony in over 250 trials that used microscopic hair comparison as evidence, including 32 trials in which defendants faced the death penalty.

The reliability of microscopic hair comparison has never been established through research, according to The Washington Post. However, after reviewing 268 cases, the FBI found that hair matches were often presented as certain during trial. Overall, FBI analysts overstated the strength of this evidence during more than 95 percent of the reviewed trials.

Errors or misconduct

Alarmingly, forensic evidence that should be reliable can still play a role in false convictions if forensic analysts have made mistakes or engaged in misconduct. The Innocence Project notes that in some cases, lack of adequate resources or training may result in innocent errors. In other cases, analysts may fabricate test results or deliberately suppress evidence that supports defendants.

Here in Houston, for example, an investigation completed in 2012 found that the misconduct of one lab technician might have affected thousands of people facing drug crime charges. According to The Texas Tribune, the analyst reportedly falsified drug test results in numerous cases. The total number of affected cases is unknown, but the man reportedly worked on over 4,900 cases while he was employed at a local crime lab.

Challenging questionable evidence

Given the various potential issues with forensic evidence, anyone facing criminal charges supported by this evidence should consider consulting with a defense attorney. An attorney may be able to help a person assess any flaws in this evidence and craft a defensive strategy accordingly.