I don't whink you need some kind of special behavior to do it... I did something similar in our very first game: http://lucho.octetostudios.com/
Maybe you will not understand the instructions because it's in spanish, but the idea of police patrolling is what I think you are looking for.
Basically what we did was that every police has an instance variable called "name" (police01, police02, etc). The patrol between points (A and B) have an instance variable called "forPoliceName" (police01, police02, etc). So, this way the patrolling points belongs only to one police instance. Then you patrolling method has to evaluate if the patrolling point belongs to the police you are moving or not and then move to it or another if the condition matches or not.
In that game, we have several police instances and every police has several patrolling points and it works perfect. Even the patrolling path changes to you if you get caught entering to a house. The police starts following you for a limited period of time and then it gets back to its original patrolling path. Take a look at it a tell me if it helps <img src="{SMILIES_PATH}/icon_e_smile.gif" alt=":)" title="Smile">