A federal public defender defends those people who are accused of federal crimes. His clients generally include those accused of federal crimes who cannot afford an attorney. A federal public defender, like any public defender, must provide a vigorous defense for his clients.
Separation of powers dictates that federal and state courts have separate court systems, and delegates certain powers to the federal government. Those powers not explicitly delegated to the federal government in the Constitution are normally left to the states. This means that states make their own criminal laws, and that most crimes are based on violations of state laws.
Although most crimes are based on state law violations, there are some exclusively federal crimes. For example, tax evasion is a federal crime that must be prosecuted in federal tax court. Certain other crimes, such as racketeering and mail fraud, are also federal crimes.
When a person commits a federal crime, he is entitled under the law to due process, which takes the form of a fair trial. He is also entitled to an attorney who can represent his interests. If an accused criminal cannot afford to provide his own attorney to defend him in court, a federal public defender will be appointed.
The federal public defender who is appointed to the case must be familiar with federal rules of civil procedure, as federal courts are different from state courts. He must also be admitted to practice in federal court, which requires additional certification beyond just taking the Bar Exam. He has to have been recommended as a federal attorney, and sworn in on a federal level.
Generally, the court will appoint a public defender in a federal case when the accused invokes his right to an attorney. This means that if a person who is accused of a federal crime asks to speak to a lawyer, a federal public defender will be appointed by the court at that time. The federal public defender will then take on the client's case.
The federal public defender's role is either to negotiate a settlement or plea agreement for his client, or to defend his client in court. In either case, this involves examining the strength of the prosecution's evidence regarding the potential federal laws that the accused broke. This will involve reviewing the facts of the case, interviewing witnesses, and conducting other investigations, and interpreting the federal criminal laws in light of the facts ascertained.