What is the religiously prescribed punishment for sexual assault, is marriage obligatory with the one upon whom that was committed, and is it permissible for her to use his messages with another woman to prove his deed?

A strange man touching a strange woman’s body is a reprehensible act for which the perpetrator is sinful and deserves punishment. The proof for this is the Hadith: "For one of you to be stabbed in the head with an iron needle is better for him than to touch a woman who is not lawful for him." This act does not oblige the man to marry the woman he touched, nor does it prevent him from marrying her. A woman should not use messages to condemn a man for this act due to the potential dangers involved, such as exposing her, and there may be circumstances she is unaware of. It is better for her not to file a complaint against him, especially if a long time has passed since the act, or if the man has repented to Allah.