Forensic science is an important part of the criminal justice system, in both state and federal courts. Forensic scientists examine and analyze evidence from crime scenes and other relevant locations to develop objective findings that may assist in the investigation and prosecution of criminals, or clear an innocent person from suspicion.

Common forensic science laboratory disciplines include (1) forensic molecular biology (DNA); (2) forensic chemistry; (3) trace evidence examination (hairs, fibers, paints, polymers, glass, soil, etc.); (4) latent fingerprint examination; (5) firearms and toolmarks examination; (6) handwriting analysis; (7) fire and explosives examinations; (8) forensic toxicology; and (9) digital evidence.

Practitioners of these forensic science disciplines are usually found in medical examiner or coroner’s offices, universities, and private practices. And the United States Department of Justice maintains forensic laboratories at (1) the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF); (2) the Drug Enforcement Administration (DEA); and the Federal Bureau of Investigation (FBI).

In Wisconsin, forensic science plays a crucial role in the criminal justice system, aiding in the investigation and prosecution of crimes as well as exonerating the innocent. The state adheres to both state statutes and federal law regarding the use of forensic evidence in court. Wisconsin has its own crime laboratories under the Wisconsin Department of Justice that provide forensic services in various disciplines such as DNA analysis, toxicology, latent fingerprint examination, and others. These labs assist local law enforcement agencies throughout the state. Additionally, forensic evidence collected and analyzed in Wisconsin must meet the standards set forth by the American Society of Crime Laboratory Directors/Laboratory Accreditation Board (ASCLD/LAB) or equivalent accrediting bodies to ensure the reliability and admissibility of evidence in court. At the federal level, agencies like the ATF, DEA, and FBI maintain their own forensic laboratories, which may also contribute to cases within Wisconsin, particularly those that involve federal jurisdiction or cross-state matters.