I think it's FACE/OFF, isn't it played by Nicolas Cage? It's about the police investigating the criminal's background and exchanging faces with the criminal, but the criminal escaped, and this time it was confidential, so the police were put in prison.

The following is a detailed introduction (it should be the movie you mentioned)

Face to Face is an action movie starring Nicolas Cage and john Travolta. The story tells that the policeman Theon (travolta) and the gangster casto (Cage) are sworn enemies. In a confrontation, Custer accidentally shot and wounded Theon's five-year-old son, and they got into trouble. In another arrest, casto fell into a coma and became a vegetable, and his younger brother was jailed. The police accidentally knew that they had planted a bomb in Los Angeles, but the younger brother refused to confess, so the police had to take a risky step: let the plastic surgeon change casto's face, his body shape and voice for Theon, so that Theon could sneak into the prison and talk about casto's younger brother.

Unfortunately, casto woke up in a coma. He forced plastic surgeons to change Theon's face for him and killed a bunch of people who knew about secret surgery. Criminals have turned into aboveboard policemen, not only releasing their brothers in prison on the grounds of summoning secret witnesses, but also backed by huge government resources.

Theon accidentally escaped from prison, and the first thing he did after he got out of prison was to find a way to get justice. As casto, he turned to casto's girlfriend for help and tried to prove to his wife that he was Theon. In the end, evil finally defeated evil, Caster was brought to justice, and Theon was restored to his original appearance.

Above, I hope to help you.