Legal Question in Criminal Law in Massachusetts

They can probably enter if they see someone underage who is intoxicated outside. There are two potential justifications for the entry: probable cause to believe that alcohol is being served to minors, and to generally check on the well-being of other occupants. It would be necessary to read the police report to give you a solid opinion, however. If they don't see an underage drinker they probably can't enter unless the person who answers the door refuses to turn down the music, or if they see people passed out from the doorway, or something like this. Hope this helps.