Legal Question in Criminal Law in Maryland

Sure, why not. You will of course have to perjure yourself by going to court and claiming to be that person. Perjury is a felony, if they find out the lie and charge you with it, you could be convicted and then serve an additional (maybe longer) sentence. You will also have the conviction for whatever the charge you are wishing to stand-in for. If, however, your question pertains to a situation in which the WRONG person was arrested, and you are truly the guilty one, this can easily be fixed. Just go to Court and tell the State's Attorney/judge.

You and the person whom you are trying to protect would face a number of charges for which both of you might serve time, perhaps more time than the person whom you are trying to protect might be facing. It ain't worth it.