District attorneys are the top prosecuting attorneys for state crimes occurring within their counties' borders. DAs are typically elected by county residents, or in some cases, are appointed under state law. A DA's office participates in criminal investigations and determines whether to file criminal charges. DAs work to reach plea deals with criminal defendants, and try criminal cases before judges and juries when negotiation fails.

Criminal Investigation

DAs play investigatory roles in criminal cases, both independently and by working cooperatively with local and state police. They take victim statements, conduct witness interviews, gather facts, and compile and analyze forensic evidence to build criminal cases. DAs also manage special units designated to investigate certain crimes. For example, these units might focus on investigations into sexual abuse, white collar crimes, elder abuse or cyber threats.

Charges and Grand Juries

DAs make the final determinations on whether to prepare and file criminal charges in court against alleged criminal perpetrators. In some circumstances, DAs must convince grand juries, which are comprised of ordinary U.S. citizens, that criminal charges are justified. For example, in Florida, DAs can independently file any criminal charge except first degree murder. The DA must obtain an indictment, or approval, from a grand jury to charge a person with first degree murder.

Court Work

DAs represent the public's interest in court proceedings relating to criminal prosecutions. They attend arraignments, bail and motion hearings, and if needed, take criminal charges before judges and juries at trial. In court, DAs examine eyewitnesses as well as expert witness such as medical examiners. DAs also present evidence, such as a murder weapon or surveillance tapes, to juries. If a convicted criminal appeals a guilty verdict, the DA's role also includes defending the public's position on appeal.

Ethical Duties

DAs are elected to represent the citizens of their counties. They are non-partisan and held to high standards of legal ethics. They are forbidden from frivolously bringing criminal charges. They also must take reasonable steps to inform an accused criminal of his legal rights. DAs also must inform the court of any new evidence they discover during prosecutions which may exonerate defendants.