I just played through SWAT 2, an old top down RTS game where you can either play a campaign as LAPD SWAT, or as an imaginary terrorist group. Both campaigns are really interesting, and the game must have been amazingly innovative in terms of concept for the time it came out. It was created in collaboration with the historical founder of SWAT and was probably one of the first games to have realistic police procedures and policy. Officers from your roster could be suspended or terminated for using deadly force. As a terrorist you could abduct people and Patty Hearst them in order to replenish your ranks. Badly injured officers would be unavailable for a certain number of missions. Badly injured terrorists, being unable to get super socialized police health benefits, would be considered mangled after the mission and would be unusable for the rest of the game. Both sides had to manage their budgets; if the budgets fell to low you wouldn't have enough funds to deploy your teams and it would be game over. The events of the mission could result in good or bad publicity that could also shut you down, or boost your funding. All in all it was a real delight to play.
One thing I especially liked that isn't generally implemented even today is that SWAT can deploy K9 units. In many cases if as SWAT you try to arrest someone the suspect will start fighting with the officer and will often start shooting. (IMHO realistically they should have implemented making the whole squad tackle the suspect together, but they didn't, and only 1 officer can try to arrest at a time.) But if you instead use an officer with a K9 unit as long as the officer gets close enough to the suspect, the suspect is pretty much owned. And if you think about it, that's pretty realistic. I'd like to see anyone try to brawl with a trained dog. This was nicely balanced, though, because if you tried to use K9s and tear gas at the same time the gas would disable your K9, so you really had a binary choice about whether you were going to try to use dogs, or gas. AND, speaking of gas, you could actually lose points on procedure for using unsafe amounts of gas, which is awesomely realistic, and is almost never implemented in games nowadays.
The one major irritation for me was the poor AI. As SWAT, you could direct a team to make entry into a room, but there was no way to direct them to automatically open fire on suspects with a high ready weapon. You had to go through a clunky interface and manually fire most of the time. Sometimes your officers would fire automatically but it wasn't clear when they would and when they wouldn't. For some reason the game let you toggle your snipers to automatically fire at any in-policy targets but there was no such toggle for your officers.
Likewise in the terrorist campaign if you weren't paying attention sometimes your terrorists would start surrendering to SWAT officers, even when crouched behind cover and armed to the teeth with grenades, rifles, and body armor.
Basically, the biggest problems with the game were micromanagement, and irritatingly unpredictable AI. I can understand how an unpredictable AI could be realistic in some ways, but come on, what SWAT officer would not open fire on a suspect with a high ready weapon?
Also, even though there was gas and flashbangs, there was no way to open a door from the side and flash the room properly. You could mirror the door, pry it open, batter it down, deploy breaching charges, but you couldn't stand aside and toss a flashbang in before making entry.
The isometric perspective made it difficult to understand whether or not a certain character had line of sight on a room. It wasn't clear whether it was possible to launch a gas grenade into a house or not because you often couldn't tell if your officer was totally lined up with the doorway or not.
SWAT 2 on the whole was such an excellent game that I wish someone would re-make it. If someone re-made it with an improved AI, and focused the development on coding up really solid room clearing procedures, the game would be a total delight.
EDIT: Sonny Bonds is on your roster of SWAT officers!