A probation violation is a serious offense that can result in extensive jail time. In many criminal cases, especially misdemeanors, probation is granted in lieu of jail time. However, when criminal defendants violate their probation they may be sentenced to serve the rest of their probation in jail. Criminal arrest warrants don't expire. Instead, they must be revoked by a probation officer, judge or other officer of the court. Thus the period of time for which they are active is dependent on the terms of probation, as well as the discretion of probation officers and judges. If a warrant is not revoked, it will remain active indefinitely.
End of Probation
A probation violation must be prosecuted during the probation period. If a probation violation is discovered after the period of probation, an arrest warrant is not valid. This does not, however, mean that a defendant can't still be arrested. The defendant will simply have to draw the court's attention to the fact that the warrant was issued after the period of probation and the warrant will be dismissed.
Some state Supreme Courts have ruled that, after the term of probation has expired, defendants cannot be arrested for probation violations -- in some cases. If the probation violation was a crime, however, defendants can be arrested even after the probation period is over. Defendants on probation should consult their attorneys on this issue, and it is never advisable to evade arrest.
Arrest Probation Violations
Probation is almost always revoked when a defendant is arrested for another crime during the period of probation. If a defendant is found not guilty of the more recent charge or the charges are dismissed, the court may revoke the warrant. This is not guaranteed, however, and defendants may need to request that their attorneys file a request to have the warrant revoked. Otherwise, they may be immediately re-arrested for the probation violation.
Probation Officer Discretion
Probation officers have significant discretion over defendants in their charge. They may revoke warrants for defendants who are no longer on probation or for defendants they do not believe to be threats to society. When a warrant is issued for failure to meet with the probation officer, the probation officer may revoke the warrant when the defendant meets with the officer, particularly if the defendant has a valid excuse for missing the meeting.
Warrants may expire in other circumstances that are not time-specific. For example, when a defendant's probation officer changes, the warrant may get lost in a computer system or may be revoked by the old probation officer. Very old warrants on minor crimes may be lost or expire when states change computer systems.