being harassed by a 13 year old!!!

What is the name of your state? Maryland
My son and a neighborhood kid fell out around 2 or 3 years ago..the kid was always making threats at school and harassing my kid after that for awhile, but it finally stopped when I called the police after he threatened to shoot him.

Now, my son and this kid have a mutual friend and ran into each other a couple weeks ago. they exchanged words about kicking each others butts, but it stopped there. My son is now in NJ visiting his dad and my air conditioning main switch kept going off, I realized someone was doing it intentionally and put a lock on it. Yesterday I came home and found my front water hose faucet had been turned on and the water left running for hours. A lawn treatment sign was also ripped up from my lawn and thrown in the street. I know it is this kid, but I have no proof. Everytime I stop one incident (like putting the lock on my ac switch), he finds something else, and I don't want this to keep escalating. His mother is useless to try to talk with, I tried in the first incidents years ago and she just denies he does anything wrong, so if I don't have absolute proof, I'm screwed.

This kid is a menance and is rumoured to have a bb gun which I'm worried about for my cats and my son's sake.

What can I do, aside from spending a fortune on security cameras to get this delinquent out of our lives??

Call the police again. Somebody is vandalizing your home/harassing you and you should make a police report about it in the event there are further incidents or real damage is done.

You may also tell the police what the history is here and why you suspect this boy is the culprit - it's possible they may elect to go and talk to the kid and his parents and put the fear of God in him (so to speak.) If time allows, they'd rather do that than have to handle a criminal mischief (or worse) crime down the road.

On a personal note, might I also suggest that when your son returns you tell him he's to have nothing to do with this boy? He needs to just turn around and walk away if he sees him and not engage in any more mutual name-calling or whatever. That seems to have precipitated this latest incident.