Hallowe'en Partygoers beat armed robber in skeleton mask

It's Hallowe'en.  You're in your apartment.  A guy in a costume comes in.  You think it's a joke.  He draws a gun and points it at you.  You run out to the courtyard, where there's a party going on.  The perp chases you out to the courtyard.  He threatens the partygoers.  He attempts to rob them too.

Then things get really fuzzy for him!  Somebody grabs a baseball bat.  Somebody else grabs a 2x4.  The perp gets clobbered.  Then, as he makes a run for it, he drops 2 guns.  He escapes in a car.

The cops find him collapsed in a nearby parking lot.  They arrest him.  They send him to the hospital with life-threatening injuries.

If  he survives the clobbering, he will face multiple felony charges.