Narvell, a 'sport' heel teaches the dog to focus on the handler, and follow direction. Obedience training builds the working relationship, and sets the pattern of control and responsiveness. I've never been an LEO, but when I've worked as a security handler I've used this kind of heel when I've been walking in public or past people who are lawfully on a work site, and my dog might be looking a bit 'lively' around them and thinking for itself too much. Having a high drive, trained dog that enjoys biting and might be actively looking for that can be a liability if the dog is not under good control. I'm sure these dogs work in some very chaotic environments, and they have to accept the handlers' authority and not just follow their instinctive drives. The fact that these officers can demonstrate such a high level of control, and have obviously put a lot of work into training their dogs shows responsibility and professionalism. This will be in their benefit when the dog has to bite a criminal, and the officer can show that the animal is maneagable and safe, and that the officer is dedicated and serious about his job.