|Since we trapped the *leader* a couple weeks ago and the shelter worker allowed him to escape, none of the ferals will go near the traps.
Sounds like you need to use a drop trap and if you aren't working with a TNR group, I would encourage you to try to find one in your state. The benefit of a TNR group is that they could pull their resources and hopefully assist you in attempting the entire colony to be TNRed. The local shelter most likely would take the cats and simply euthanize them. Remember that these cats are following their instincts and they deserve a chance to live (even outdoors) over being euthanized. Removal of cats just gives an opportunity for other intact cats to come in their place.
In addition, it is wise to not feed for a couple of days prior to trapping so that the cats are really hungry and more likely to go into the trap (if anyone else in the neighborhood feeds these cats..they would also have to stop feeding them during that time). If the cats know that if they don't go in the trap, they will still be fed, they are obviously going to wait. Another option is to start putting the food in the traps but having the trigger of the traps set so the trap does not go off. Once the cats are more comfortable going into the traps, you could then set it to go off.
Warm, deboned, deskinned KFC is a favorite bait here.
Below is a list of TNR groups by state:http://www.alleycat.org/orgs.html
As for Allister...it great that you have a sighting of him. Even if the other cats were not visible, I'm sure that their scent is all over your property and that is what is keeping Allister from running to you. Can you attempt to trap him again in the area where you are seeing him?? It's obvious he wants to come home but needs some assistance.