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Wednesday, June 17, 2020

Problems in Forensic Science

     Practitioners of forensic science fall generally into three groups: police officers who arrive at the scene of a crime whose job it is to secure the physical evidence; crime scene technicians responsible for finding, photographing, and packaging that physical evidence for crime lab submission; and forensic scientists working in public and private crime laboratories who analyze the evidence and, if the occasion arises, testify in court as expert witnesses. While uniformed police officers and detectives may be trained in the recognition and handling of physical evidence, they are not scientists, and do not work under laboratory conditions. As a result, a lot can, and does, go wrong between the crime scene investigation and the courtroom.

     Television series like "CSI" generated public knowledge and interest in forensic science, even ramping up scientific expectations for those involved in real-life criminal investigation and prosecution. Prosecutors called this the "CSI effect," the expectation among jurors that the prosecution will feature physical evidence and expert witnesses. The CSI effect also caused jurors to expect crime lab results far beyond the capacity of forensic science. Some prosecutors either eliminate potential jurors who are fans of "CSI," or downplay the necessity and importance of physical evidence as a method of proving a defendant's guilt. Prosecutors who lost cases have been known to blame their defeats on the CSI effect. Criminal justice scholars who have investigated the CSI effect disagree over whether it had much impact on trial results.

    While public expectations of forensic science are high, persistent problems within the various forensic fields have kept scientific crime detection from living up to its full potential. Because a shortage of qualified personnel caused DNA testing logjams, rapists, pedophiles, and serial killers have been given extra time to commit more crimes. The shortage of DNA analysts also placed a heavy burden on crime lab personnel, creating problems of quality control. In the past few years, dozens of crime lab DNA units were temporarily closed when audits revealed sloppy work, scientific errors, unqualified analysts, weak supervision, poor training, and evidence contamination. Even the highly regarded FBI Laboratory experienced problems with DNA analysis and other forms of forensic identification. Crime labs in Detroit, Boston, Raleigh, Houston, New Haven, and Los Angeles have had serious quality control problems.

     Ironically, advances in DNA technology exposed problems in other fields of forensic science. For example, DNA analysis revealed that experts overstated the identification value of human hair follicles and bite-mark impressions. Hundreds of criminal defendants, if not thousands, were sent to prison on what many experts considered unreliable forensic evidence.

     A critical shortage of board-certified forensic pathologists adversely affected the overall quality of homicide investigation. Overworked forensic pathologists are prone to take shortcuts and make mistakes. In cases of suspicious death, autopsies were not performed.

     The field of latent fingerprint identification, while still considered the gold standard of forensic science, came under attack as a result of a handful of high-profile misidentifications. These cases revealed that not all fingerprint examiners are properly trained, and that many have either failed or never taken proficiency tests. Moreover, many fingerprint experts lacked scientific objectivity. This was particularly true of examiners who, as police officers, saw themselves as part of a law enforcement team. Forensic scientists must be loyal to their science, even when it displeases the people who employ them. This takes courage and independence.

     There are fakes, incompetents, and charlatans in every profession, but over the years a series of high profile cases featured the so-called experts from hell, forensic scientists whose false testimony helped convict innocent people. Many of these experts were hired guns willing to testify for whatever side was willing  to pay for their testimony. It's alarming how long these phony forensic scientists practice before they are exposed and defrocked. Forensic science is also plagued by well-meaning but incompetent practitioners as well as experts who are either blinded by media attention, or bow to prosecutorial pressure. Maintaining a firewall between science and criminal prosecution is a constant challenge, one that is not always met.

     Jurors are often called upon to make judgments in trials in which experts representing each side the case offer contradicting opinions. When jurors are faced with opposing experts, they tend to disregard the physical evidence entirely. The dueling expert problem can seriously diminish the credibility of forensic science itself. Judges reluctant to exclude the testimony of witnesses who are not real experts, place the problem on the laps of jurors who are not qualified to distinguish the true scientists from the fakes.

     Most of the problems in forensic science are caused by personnel shortages, poor quality control, the inherent difficulties of crime scene investigation. These are pressures imposed by the adversarial nature of our trial process, the lure of pseudoscience, and the evolving character and complexity of science itself. Over the past twenty years, the emphasis in American law enforcement has been the escalating war on drugs, anti-terrorism, and controlling inner city street gangs. Criminal investigation took a back seat to these priorities. And now, law enforcement itself is under attack. 

1 comment:

  1. Jim,


    Being in law enforcemnt for nearly 25 years, I can attest to how "The Drug War' has taken precedent for politicians and chiefs(same thing aren't they?).
    What looks better a presser with guns,drugs and money or a presser with no fancy props but discussing how detectives have solved a string of burglaries using old skills like-fingerprints, interveiews, leg work etc.

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