Sherlock Holmes. Hercule Poirot. Nancy Drew. Dexter Morgan. Benson & Stabler. All famous detectives from the media who use forensic science to solve their crimes and catch the culprit. Forensic evidence taken from crime scenes has long been a fixture in criminal trials and law enforcement. The weight of forensic evidence in a criminal trial is great, and it has often been a crucial factor in determining someone’s guilt or innocence because it is regarded by law enforcement and the public as trustworthy and reliable as standardized scientific methods.
Forensic science has been used for centuries and was even used in antiquity
to determine facts about crimes. In the very first written account of
forensics from the year 1248, an investigator was trying to determine
who murdered another man with a sickle. The investigator ordered a group
of townsfolk to bring their sickles so he could test each of them and
compare the cuts on an animal carcass to the death wound. When everyone
gathered, though, the flies were attracted to one person’s sickly
that still had blood residue on it from the murder. The suspect confessed
his crime. Other communities from antiquity would test the dryness of
suspects’ mouths to determine guilt by making them put uncooked
rice in their mouth and seeing if it stuck. This was based on the (accurate)
assertion that guilty people tend to have drier mouths and less saliva
than innocent people. More often than not, though, techniques were shoddy
and differed from crime to crime and sometimes left criminals on the street
while innocent men were imprisoned.
Forensics have come a long way since those days. As history progressed, the foundation of modern pathology was laid by large advancements in medicine and surgery. As early as 1773, a test was developed to determine if a person had died from arsenic poisoning. In 1836, the test was used to convict a suspect who had poisoned someone with arsenic. Meanwhile, the procedures of police investigation in general were becoming more and more standardized, which led to more accurate criminal trials and convictions. By 1909, the first school of forensic science was established at the University of Lausanne in Switzerland.
Despite a long history closely connected to both law enforcement and pathology, forensic science still falls short in some areas and has even come under fire recently for its faulty practices that put innocent people in prison, sometimes for life. The following practices have come under fire for not having a solid backing of proven research to lead to the assumption of scientific merit:
- Fingerprints. The idea that each human on Earth has a unique fingerprint, different from any else’s, is still prevalent among the law enforcement, forensic scientists, and the general public. However, a recent article by the New York Post has questioned that assumption and pointed out that there were no set standards for analyzing a fingerprint. From measurement criteria to comparison points, there is no set standard for evaluating a fingerprint.Famously, an Oregon attorney was falsely implicated in train bombings in Madrid, Spain after having the same fingerprints as the perpetrator.
- Comparative Bullet-Lead Analysis. This once-popular forensic practice was used by the FBI for four decades before it was abandoned for having no real scientific value. The general idea was that each batch of bullets had its own unique elemental makeup that was different from any other batch of bullets. Forensic scientists would test a bullet found at a crime scene against bullets that the suspect had in his or her possession to see if they were the same.
- Bite Mark Analysis. Forensic dentistry is often used to identify remains, but it has been criticized recently for false bite mark identifications. A study by the American Board of Forensic Odontology found that there was a 63 percent rate of incorrect IDs during an informal workshop during a meeting. Though the study didn’t take place in a scientific setting, people who were implicated by bite mark analysis have already been freed from false imprisonment based on later DNA testing.
- DNA Testing. Considered the “gold standard” of evidence, advancements in DNA testing has released a number of innocent people from false imprisonment over the years for crimes they were falsely convicted of. Scientists in Israel have effectively fabricated blood and saliva DNA samples without obtaining any original tissue from a person. The authors insist in the paper that even a biology undergrad can engineer a crime scene if they had access to a DNA database. Furthermore, false DNA samples taken from crime scenes have implicated people who were in no way tied to the crime, some lucky enough to have strong alibis. While police and forensic scientists frequently claim that it is very highly unlikely for two DNA samples to match, a recent audit of Arizona’s DNA database showed that 150 pairs of DNA matched each other closely enough to allow for a conviction.
These assumptions have left people wondering why forensic science is considered a science at all. In reality, forensic science is found to be lacking the quality procedures, standards, and scrutiny that is found in the scientific community. Forensic science has been lauded as true as science itself by law enforcement, when really it is riddled with inaccuracies. In a 2009 Supreme Court decision, it was found that crime laboratory reports must not be considered against criminal defendants if the author (forensic analyst) was not available for testimony and cross-examination during the trial. Essentially, the Supreme Court asserted that forensic evidence was no longer without its flaws and can easily be influenced by bias and manipulation.
The general consensus in regard to forensic evidence right now is that without it, law enforcement would be lost and their ability to solve crimes and charge the correct criminal would be greatly compromised. In light of recent revelations of the inconsistent reliability of forensic tests and procedures, though, their limitations should be recognized. In the meantime, safeguards, accreditation, repeatable and universal standards, and thorough review and oversight committees should be implemented in order to further advance and improve the field.