Based on how it is portrayed in TV and movies, forensic science can seem infallible. Police officers on TV shows seem to use amazing technology and deductive skills to determine exactly how a crime occurred, identify suspects, and prosecute those who are guilty. However, these fictional depictions of criminal investigations are very different from how cases are handled in the real world. In reality, forensic science is often unreliable, and in many cases, police must rely on guesswork, or they may approach a case with biases and use forensic investigation methods to confirm their suspicions. Far too often, “junk science” is used during the criminal prosecution of suspects, and evidence may be accepted as incontrovertible proof of guilt without questioning its flaws.
Reasons Why Junk Forensic Science Is Unreliable
There are a variety of investigation methods used by police officers, and in some cases, supposed "experts" will encourage the use of certain techniques that are questionable and unreliable. In many cases, these methods will be based on the subjective interpretations of investigators and oversimplifications of complex factors. "Experts" often have limited evidence or scientific research to support their claims, yet they will portray their methods as conclusive, without acknowledging the possibility of errors.
Unfortunately, junk forensic science is accepted as valid evidence in criminal cases all too often. Judges may allow "experts" to testify without questioning whether their methods are valid or reliable. Defendants may be convicted based on claims that a person's interpretation of evidence is absolutely correct, even when they have been found to be incorrect in the past.
...