First I would like to say I agree with just about everything
@punisher73 has said, as such some of the stuff below may seem repetitive. My context, over 18 years on the job in a small city of 25000 people and a per capita crime rate on par with Cities like Philadelphia, Chicago etc. I also used to be on a Street Crimes/Narcotics Enforcement Unit that served high risk search warrants and the like.
1. In a Law Enforcement class I don't think you can focus on a single martial art. Most traditional Martial Arts, especially grappling arts, don't take into account all of the tools on the duty belt, whether it be in terms of retention or accessibility during an encounter. Note I said traditional. There are Combative Systems (PPCT, LOCKUP etc that do account for it to my knowledge)
2. Personally I don't think simply teaching techniques is enough. I believe a Law Enforcement combative system needs to also address the fundamental principles of an encounter. LE combatives, just like all training based on the UoF continuum, is about stopping resistance and aggression before we have to escalate to a higher level of force. The first step in achieving this goal is to not teach physical techniques but to instruct the LEO in pre-attack indicators. An officer well trained in this regard will be able to use the techniques taught later to end a fight before it starts. This section should also cover proper articulation for the purposes of reports, court proceedings etc.
3. After that you need to have a system that A. Explains to the Officer the physiological reactions of a real violent encounter and B. that the actual techniques involved should be based on these as well. The problem with most such training is that after the training is over Officers don't end to practice a lot on their own. As such the techniques should rely primarily on gross motor function as those skills aren't as perishable as fine motor function.
I personally study Wing Chun and Filipino Martial Arts, specifically Inosanto Kali. Many of the techniques in both these arts though are fine motor skills. I practice almost every day though so it works.
4. After the techniques you need to teach realistic scenarios. This may require taking the mats somewhere where you can not only control lighting but also maybe get a patrol car in there. Why? Well there may well be times where the conflict happens when your only real source of illumination is the light bar, maybe take down lights etc. You might want to blare loud music or have the sirens going as well. You may even want to forgo the mats entirely. I have seen officers quite skilled in wrestling give themselves concussions because they did take downs that work fine on mats, because the impact to their own head is cushioned, due to muscle memory, forgetting that tarmac is far less forgiving. Also there is NOTHING that sucks more than doing a take down and having your radio or gun jammed into your hip.
5. Also keep in mind what punisher said. Joint locks and the like should not be the first techniques attempted against actively aggressive/resisting subject. Often the bosses, if they did not go through combatives training on the "way up", will default to something like Judo or wrestling because they are simply concerned with the minimal use of force, but striking may well be required, even if a suspect is already on the ground, in order to properly and safely apply restraint maneuvers.
6. You may also want to integrate baton training into the curriculum.
With all the above in mind it may actually behoove you going to the bosses and saying "hey, Judo and Wrestling clearly work but there are "holes" in their application for LE use. Here is an upcoming train the trainer school on LE Combatives coming up and I would like to go to it.
@MAfreak I at least have used the expandable baton for escorts and I think that is appropriate for most officers. Personally I have also used it for quick disarms when people have had sticks and occasionally locks. The thing is, all of the above are, to an extent, fine motor skills. I train in Kali as I said and practice regularly so it works for me. I would only suggest the escort use, and perhaps as a lever, when you get one of those knuckleheads who lies on their stomach and interlocks their hands for your typical officer though. They will, more than likely, not be training the way I do and so not do things appropriately and even risk losing their baton to the suspect.