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 Arizona, forensic science is a critical component of the criminal justice system, utilized by both state and federal courts. Forensic scientists in Arizona engage in the examination and analysis of evidence from crime scenes, contributing to the investigation and prosecution of criminal cases, as well as potentially exonerating the innocent. The state adheres to various standards and protocols to ensure the reliability and integrity of forensic evidence. Arizona has its own state crime lab, as well as local labs in various counties, that perform many of the forensic disciplines listed, such as DNA analysis, forensic chemistry, and latent fingerprint examination. Additionally, Arizona law enforcement agencies may collaborate with federal forensic laboratories, such as those operated by the ATF, DEA, and FBI, for specialized forensic services. The admissibility of forensic evidence in Arizona courts is subject to state statutes, case law, and the rules of evidence, which include considerations for scientific validity and expert witness testimony.