The police have already been out, so there is already somewhat of a record of the event.  If you are concerned, however, that the event was not property documented, then I would set up a meeting with the police chief or a detective to express your concerns. That addresses the reporting issue... but you still have a problems with noisy neighbors.  If it continues, consider hiring an attorney to send a simple demand letter... to the effect of straiten up or we'll sue.  It communicates a message of 'straiten up', but is also takes you out of the middle and the dred of having to deal with the lousy neighbor.