A forensic chemist's job is to identify and characterize the evidence as part of the larger process of solving a crime.
Forensic chemists apply knowledge from diverse disciplines such as chemistry, biology, materials science, and genetics to the analysis of evidence found at crime scenes.
That is why this field is also know as Forensic Science due to it overlapping many different disciplines.
They spend time preparing and giving testimony in court, most Forensic Chemists work in government labs, these labs are connected to a federal, state, or local police department and medical examiner's office, they are also employed by law firms to give evidence in Court.
Forensic chemistry is unique among chemical sciences in that its research, practice, and presentation must meet the needs of both the scientific and the legal communities.