1, tainted witnesses shall not be exempted from punishment, and whether they are exempted from criminal punishment depends on the specific circumstances of the crime. There is no tainted witness exemption system in China's current criminal legislation, but the internal spirit of this system is reflected in some criminal systems. If a criminal suspect or defendant is willing to expose another person's crime, provide important clues or actively assist in the pursuit, the provisions of the law on meritorious service, significant meritorious service and discretion not to prosecute may be applied according to the specific circumstances.

2. Legal basis: Article 390 of the Criminal Law of People's Republic of China (PRC).

The punishment for bribery stipulates that those who pay bribes shall be sentenced to fixed-term imprisonment of not more than five years or criminal detention and fined; Whoever seeks illegitimate interests by bribery, if the circumstances are serious or cause heavy losses to the interests of the state, shall be sentenced to fixed-term imprisonment of not less than five years but not more than ten years, and shall also be fined; If the circumstances are especially serious, or the interests of the state suffer particularly heavy losses, they shall be sentenced to fixed-term imprisonment of not less than 10 years or life imprisonment, and shall also be fined or confiscated.

If the briber voluntarily confesses the bribery before being prosecuted, he may be given a lighter or mitigated punishment. Among them, if the circumstances of the crime are minor, which plays a key role in the detection of major cases, or if there is significant meritorious service, the punishment may be mitigated or exempted.

Second, what are the characteristics of tainted witnesses?

1, the tainted witness is the first person to know the case;

2. Having committed a crime that conforms to the provisions of the criminal law is a real crime that has not been punished by punishment;

3. On the basis that the state procuratorial organ promises to reduce the charges against him or exempt him from criminal responsibility, testify against others as a prosecution witness. That is, the person testifies for the national public prosecution agency in exchange for being exempted from criminal prosecution or being given a lighter or mitigated charge.