Forensic evidence is scientific-based proof that can be used to determine a suspect’s guilt or innocence. It can include everything from bloodstain patterns to a suspect’s fingerprints. These types of physical traces undergo careful scrutiny in a laboratory setting to extract valuable information for use in criminal cases. Unlike eyewitness testimony, which can be influenced by faulty memories or other factors, forensic evidence provides objective data for the courts to evaluate.
For example, DNA analysis can identify a suspect by matching samples from the crime scene to profiles in law enforcement databases. This is especially useful in violent crimes, as it can provide a direct link between the perpetrator and the victim.
Another example of forensic evidence is trace evidence, which involves collecting and testing small particles at a crime scene to establish or exclude an association between a person and the crime scene or victim. For example, gunshot residue left on a suspect’s hands from handling the weapon can be collected using a cotton swab and tested against gunshot residue found at a crime scene.
However, despite the reputed accuracy of forensic evidence, even the most reliable methods are not immune to errors. For instance, laboratory equipment may malfunction or materials can be contaminated. Furthermore, examiner bias can also influence the results. For example, an examiner who believes that the accused is guilty will tend to interpret evidence more favorably. These errors can weaken the credibility of forensic evidence in court and should be taken into account by an experienced attorney.