Federal prosecutors represent the federal government in
criminal cases and try to prove that a person or company committed a crime (U.S.). Some federal prosecutors are United States Attorneys (93 of them). States have a United States Attorney for each district and Assistant District Attorneys who assist them in prosecuting cases. The prosecutorÆs job is to investigate the case; decide whom to charge with what; to hold an initial and pre-trial hearings; negotiate any pleas agreements; make a motion in Limine; prosecute a trial; recommend sentencing; and take part in any appeals made by the defense. It is the prosecutorÆs job to prove that the suspect committed the crime for which he has been charged, and convince the jury of this beyond a reasonable doubt.
The defense attorneyÆs job is to convince the jury that there is a reasonable doubt that his client committed the crime of which he/she is accused and therefore that he should be/she should be found not guilty. He may be able to persuade the prosecution that there are good reasons why charges should not be filed, or that there is a legal reason why the law does not apply to a particular factual situation before the case goes to trial (Arizona). There may be weaknesses in the evidence that law enforcement officials have overlooked, or there may be others more criminally responsible than the client. The attorney evaluates the evidence to see if there is a valid case against his client. The defense attorney gathers information from prosecution witnesses, hires and manages investigators who may be able to find evidence to contradict witness testimonies, and can file pretrial motions if they find things such as evidence that would constitute unreasonable search and seizure, confessions given under duress, etc.
A defense attorney can negotiate a plea agreement with the prosecutor if he feels the client is likely to lose at trial, and arranfe for reduced charges and ...