Cooperation agreements, on the other hand, are the most commonly used instrument to compel testimony. These agreements require the defendant to incur some type of liability for his or her criminal conduct. In a cooperation agreement, the defendant agrees to plead guilty to certain agreed-upon charges, to fully and truthfully cooperate with prosecution, and to testify in any court proceeding concerning all matters asked of him or her. In exchange for the defendant’s cooperation, the government agrees to file a motion pursuant to Federal Sentencing Guideline § 5K1.1.13 This motion gives a judge discretion with respect to the defendant’s sentence, something he or she ordinarily would not possess. Upon receipt of such a motion, the sentencing judge will usually decide to reduce the sentence. This creates a powerful incentive for cooperation, and is a particularly valuable tool in the prosecution of organized crime groups.