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 Pennsylvania, forensic science plays a crucial role in the criminal justice system, aiding both state and federal courts. Forensic scientists in PA are tasked with examining and analyzing evidence from crime scenes to provide objective findings that can support criminal investigations and prosecutions, or help exonerate the innocent. The state adheres to standards and regulations that govern the practice of forensic disciplines such as DNA analysis, forensic chemistry, trace evidence, latent fingerprints, firearms and toolmarks, handwriting, fire and explosives, toxicology, and digital evidence. These professionals often work in medical examiners' or coroners' offices, academic institutions, or private firms. Additionally, federal forensic services are provided by the Department of Justice through agencies like the ATF, DEA, and FBI. Pennsylvania's forensic laboratories are expected to maintain high standards of practice, and in some cases, they must be accredited by bodies such as the American Society of Crime Laboratory Directors/Laboratory Accreditation Board (ASCLD/LAB) or the ANSI-ASQ National Accreditation Board (ANAB).