If the prosecutor is obliged to choose his cases, it follows that he can choose his defendants. Therein is the most dangerous power of the prosecutor: that he will pick people that he thinks he should get, rather than pick cases that need to be prosecuted. With the law books filled with a great assortment of crimes, a prosecutor stands a fair chance of finding at least a technical violation of some act on the part of almost anyone. In such a case, it is not a question of discovering the commission of a crime and then looking for the man who has committed it, it is a question of picking the man and then searching the law books, or putting investigators to work, to pin some offense on him.

- Robert Jackson. On Spitzer and prosecutor discretion...