probation officer

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An officer charged with assisting courts in the investigation of defendants' backgrounds and circumstances to assist in the determination of appropriate sentences and in the supervision of convicted offenders who have received a sentence of probation.
• noun A similar officer charged with investigating the backgrounds and circumstances of juveniles to determine appropriate outcomes in delinquency proceedings and with supervising those adjudged delinquent.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A law enforcement officer who supervises offenders who have been released from incarceration and, often, recommends sentencing in courts of law.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the officer of the court who supervises probationers