Whether investigating misdemeanor cases or felonies, police investigate criminal incidents and gather evidence in order to bring offenders to justice. The criminal investigation process establishes legal guidelines for bringing in law enforcement, forensic specialists, and legal authorities to an incident and building a case for prosecution in court. It is vital to the criminal justice system that the process be carried out properly. Any mistakes could cripple a case, set the guilty party free or wrongly imprison an innocent person.
A critical component of the process is the preservation of the crime scene, which requires police to take certain precautions to prevent contamination and damage. For example, blood samples must be analyzed within a specified time period and stored in the proper containers (paper bags inhibit mold growth on biological samples, while anti-static bags protect electronics). Each piece of evidence works together to support the hypothesis that an offender committed the crime.
Once the scene is secure, investigators start documenting and collecting the evidence in a structured and methodical manner. Depending on the nature of the case, this can involve a wide range of investigative tools and techniques. For instance, police officers often use specialized cameras and microphones to capture audio and video of suspects or victims. They also collect fingerprints and bodily fluids to identify a perpetrator. In addition, police may request a medical examination of a victim with the consent of that victim, which can provide valuable clues about a possible suspect.