Local and state police departments, such as city and state police, employ forensic scientists to assist in the investigation of crimes. Based on collected evidence, forensic scientists conduct crime scene reconstructions and suggest diagrams of how a crime may have been committed. This may include a trajectory analysis of projectiles, such as gunshots. They also perform specialized crime scene processing and evidence recovery, which can include taking photographs and video recordings; locating, collecting and preserving evidence; and completing investigative reports and analysis on the scene and its evidence.
Many forensic scientists work in crime laboratories operated by city, county or state governments. At these labs, forensic scientists conduct the chemical, biological and physical analysis of evidence collected at crime scenes. They have extensive knowledge of the theories and practices of biology for DNA testing and examinations of blood, hair, bone, teeth and other biological specimens collected at crime scenes. They know how to calibrate and operate scientific equipment and analytical instruments, compile written analysis and report their findings to investigators.
Federal agencies, such as the Justice Department, Treasury Department, Postal Inspection Service and Health and Human Services employ forensic scientists who specialize in a particular area of forensics, such as ammunition, DNA, explosives, trace evidence or hazardous materials. For these positions, highly technical knowledge is required in a specialty area. For example, an ammunition specialist serves as the expert regarding the wide variety of ammunition and its components. They must have extensive knowledge of firearms and how to use them, the different types of ammunition used and knowledge of new and experimental firearms being developed. The FBI has one of the largest and most comprehensive forensic laboratories in the world and employees more than 500 scientific experts. Its services are available to FBI field offices, U.S. Attorney’s offices and other federal agencies, and local and state law enforcement agencies.
Many hospitals employ social workers or forensic scientists who have a background in nursing. These professional have training in providing trauma care or trauma counseling, collecting physical evidence from crime victims and providing testimony that can be used in legal proceedings. Both social workers and forensic nurses have specialized knowledge of the legal system and have received extensive training in identifying, evaluating and documenting injuries caused by assault, sexual violence, neglect or other forms of intentional injury. After the victim has been treated for their injuries, social workers and forensic nurses collect the necessary evidence, advocate for the victim and consult with legal authorities.