The Latin term "nolle prosequi" is a formal entry in a court record which indicates that the prosecutor or plaintiff does not intend to pursue the matter. Nol-pros or nol pros as it is sometimes known may be entered at any time after charges have been filed, up until a verdict is delivered. In some legal systems, once a case has gone to trial, the permission of a judge may be required in order to enter nolle prosequi and drop the case.
There are a number of reasons why a civil plaintiff or criminal prosecutor might decide to drop a case after it has been filed in court. One reason is a demonstration of innocence. For example, if a prosecutor receives information that someone who has been charged with robbery categorically did not commit the crime, he or she will ask to drop the case, since there is no point in prosecuting someone who is innocent.
Another reason might be a situation in which a case cannot be proved. This can sometimes be hard to discern before charges are filed and charges may be filed anyway even when a case is moderately weak in the hopes that additional supporting material can be gathered to make the case stronger and worth pursuing in court. However, if it becomes evident that it will be difficult to prove the case, the prosecutor or plaintiff will drop the case and the record will bear a note of nolle prosequi to indicate that the charges were dropped.
Demonstration that there are fundamental flaws in the case as presented may also be cause for nolle prosequi. This can occur during trial as the prosecutor or plaintiff has a chance to see the other side in action. If, for example, a witness is discredited on the stand and that witness is key to the case, nolle prosequi may be filed because the case is too flawed to pursue.
This term, which translates as “we are unwilling to prosecute,” is one of many Latin terms which continues to be used in legal practice. Care is taken before requesting that a note of nolle prosequi be entered so that the charges can be dropped. The person dropping the charges does not want to make a mistake and give up on a case which actually does have legal merit and would be worth pursuing. In some cases, a judge may overrule the request and insist on hearing the trial anyway.