Look, first of all, I am sorely disappointed that the good guy that night went out unarmed and so didn't get his bag limit of dirtbags.
However, zapping punks ala Charles Bronson is illegal and it remains assault and battery to be fake zapping them with paintball guns.
So, shy of the nation getting some stones and deporting all of these punks' families and shy of actually expecting the police to solve a difficult crime, there are three basic options:
1. Move. (Flee). This is probably the eventual move just through the progression of my career, but right now the housing market is too soft to get out of my house and the business end is dicey enough that moving up could be a stretch best not made at the moment.
Additionally, I am a fan of the sentiment of Col. Cooper that one cannot confront evil by fleeing from it. In part, this gangbanger phenomenon has spread because people flee or duck their heads about it. Then it takes root in their community permanently and follows those who fled out to the suburbs, just like here it took hold of the "bad" neighborhoods and now reaches out to affect the decent ones.
Just one bad kid from one Mexican immigrant family has this whole thing going. No tagging in the ten years I have been living here and then an explosion. No one but school kids used the drainage ditch shortcut and now delinquents tag the fences of the homeowners who back to it.
2. Zap them. This is of course highly illegal and barely merits mention. Had I been the next door neighbor on the night of the shooting, the cops would have had little trouble finding a car or suspects riddled with 30+ 7.62x39 rounds. Call that a lost opportunity on the part of the local good guy but it is lost nonetheless. One cannot reasonably stake out, or hunt down and kill the wannabes and expect to not trip up and get caught. I view this option as being in the realm of fantasy.
3. Area denial. This is the option I am exploring because it is realistic at this moment in this economy. Upon overnight reflection, I know exactly where to get at some Himalayan blackberry root balls. I examined the approach at the ditch in great detail this morning. If the city does not approve our coming request to gate off the ditch on both ends with some security fencing to deny access to it, I have decided that this fall I am going to introduce the blackberry canes into the ditch on both sides and let them become the barriers instead. The first benefit to this is that it is rapid and untraceable. Anyone living in the PNW on the "wet side" knows that berries like the ones I propose to use are viewed as "weeds with fruit" and grow into what are aptly named thickets, with an array of thorns eventually more effective than concertina wire. The second benefit is that once established, the bangers are too lazy to clear them, so they will choke off their access via a lack of their will to clear brambles that can grow as much as 23 feet per cane per growing season and eventually can establish a density of up to 500 canes per square meter. Thirdly, if the city even bothers, at most they will spray them, but only after they are established, and even dead, the brambles are an obstacle. Also, even if they do clear them, I will reestablish them and it will look just like indomitable nature won't be denied.
That said, the other end of the equation remains untackled. There is a LDS church across from the target wannabes house. I was hoping to propose at the next neighborhood watch meeting that we all chip for a wifi security camera and approach the church for it to be placed on one of the church's parking lot light poles and have it conspicuously pointed at the target's house so that he'd know all about it. Maybe that and some postings around the neighborhood that certain undesirables were being monitored whenever people felt like loading up web page of the camera and that would send a message. The hope here is that the knowledge that the target wannabe's family is under 24/7 surveillance will get them to hobble the wannabes activity, or failing that, provide evidence to the police of gang activity.
The more aggressive and definitely illegal thing to do to convince the trouble family to move on would be a false flag operation that undermines their sense of security far more than they can psychologically handle. I am not at the point where conspiring about this with the fellow vets in our neighborhood watch is worth the time or energy. It remains intriguing though.
Right now we have to use the "proper" means and partnering with the police to combat the problem. 
