First and foremost, you must be able to demonstrate your proficiency, level of training, documentation of training and generally, some form of certification. After that, there are other concerns. Does the group know how work in a potential crime scene. Is or has the group in the past, been media hounds. Does the group know how to follow instructions from the command post.How did you get LE to call you out in time for the person to be found alive?
Secondly, LE must know that the group is available for call outs. There is no drama in having them respond. No "in-fighting" among those responding. The group will come when called, not when it's convienient for them.
Those are just some of the considerations that you/your group must be able to display. Gaining the trust of law enforcement is not all that easy. It can be done, but it's not as easy as showing up and saying: We're SAR and here to help.