Damn
Sorry you had to go through that. Hang in there, man.
Criminal behavior tells us the old addage "a good criminal returns to the scene of the crime" holds true. Look for anyone whom observes your Z with a cheese-ball expression on their face. Or someone acting strange if they come around your Z when normally they would never do it.
Patiently grill anyone near your apartment whom says anything about the scratch marks.
LEO's normally catch bad guys that are nearby because as humans we instinctively "twitch" when we know we're about to get in trouble (bad drivers drive worse when squad cars are on patrol close by).