Legal analysis: criminal understanding is a kind of legal document issued unilaterally, which belongs to unilateral behavior. As long as it is issued, it has legal effect without the signature of both parties. The premise of criminal understanding is that a settlement has been reached between the victim of a criminal case and the criminal suspect or his family, and the criminal suspect and his family may or may not compensate the victim for the loss. Criminal understanding is generally completed between the date of filing a criminal case and the court's verdict, which has the effect of discretionary mitigation and lighter punishment in criminal law. Therefore, the focus of the letter of understanding should be to make it clear that the victim has understood, and at the same time, the victim requests to be exempted from investigating the criminal responsibility of the defendant or criminal suspect.

Legal basis: Criminal Procedure Law of People's Republic of China (PRC).

Article 288 In the following cases of public prosecution, if the criminal suspect and the defendant sincerely repent and obtain the understanding of the victim by means of compensation for losses, apology, etc., and the victim voluntarily reconciles, both parties may reconcile:

(a) due to a civil dispute, suspected of criminal cases stipulated in Chapters IV and V of the Specific Provisions of the Criminal Law, and may be sentenced to fixed-term imprisonment of not more than three years;

(two) criminal cases of negligence other than dereliction of duty that may be sentenced to fixed-term imprisonment of not more than seven years.

If a criminal suspect or defendant intentionally commits a crime within five years, the procedures specified in this chapter shall not apply.

Article 289 If both parties reach a settlement, the public security organ, the people's procuratorate and the people's court shall listen to the opinions of the parties and other relevant personnel, examine the voluntariness and legality of the settlement, and preside over the making of a settlement agreement.

Article 290 The public security organ may make suggestions to the people's procuratorate for leniency in cases where a settlement agreement is reached. The people's procuratorate may put forward suggestions for lenient punishment to the people's court; If the circumstances of the crime are minor and there is no need to be sentenced to punishment, a decision not to prosecute may be made. The people's court may punish the defendant lightly according to law.