Structure is going to vary greatly from team to team. But yes, there are several key positions. From my experience there are several duties that are divided up, but most of us cross-train. I would say that most departments still divide into a perimeter and breach team.
Breach (the guys that enter the house/building)-
Shield Man: The guy carrying the big honking shield up front. Only a pistol.
Munitions: Someone tasked to carry flash bangs and chemical munitions. SMG (I use a 9mm* M4, not an H&K. Have shot both, prefer M4).
Ram: Carrys the door ram. May be limited to a pistol, but could have an SMG if have the right kind of sling. You toss the ram after you use it.
Team Leader: Self-explanatory. SMG.
Medic: Tries to stay out of the fight, but actually goes in with breachers. Carries a large backpack medkit. Pistol.
Shotgun: Not always present. Shotgun can be used to fire small chemical munitions, less lethal rounds, and rounds to destroy door hinges.
Others: The main members of the, "stack", normally all armed with SMGs.
Other equipment divided between members would be more chemical munitions, flash bangs, medical gear, zip ties, and special breaching tools other then the ram.
Exact numbers in a team will vary considerably by department and target.
The breach guys don't do anything really until they are going to breach. The elements below do the long-lasting work.
*Note: Some departments are considering 5.56mm or another light rifle round instead of a pistol round in an SMG. The past worry has been over-penetration. Special kinds of non-penetrating ammo and info that 5.56mm doesn't penetrate through walls as much as feared is leading to discussion of a change. But, I can't say I know of a department that has actually taken this leap yet.
Perimeter
Varies greatly in numbers. Could be only 2 for a small house, but often more and usually involves extra in the form of patrol officers. Perimeter are not just "snipers", but also the observation team. They have a system of radio calls that allow them to quickly report when a bad guy is in a window, someone is coming out, etc. Not always armed with a true sniper rifle, sometimes only an assault rifle due to being close in an urban environment.
Support
This could include more patrol officers, chase vehicles, EMTs, firemen, and a command and control vehicle (the brass in a nearby safe area with extra commo, video, negotiators, etc).
Planning/Stages
Zemekis said:
-Recon
-Briefing
-Engagement
-Post Operation Analysis
maybe?
Actually you pretty much got this right. But, these stages often get thrown out the window especially when you get called at 3 AM and the team has to do something 10 minutes ago. While some departments may have formal steps, I would guess most do follow what you postulated, but in a more unofficial sense. Lots of the Recon may have happened weeks before the operation when considering a search warrant entry. The night of the operation, Recon would be someone keeping an eye on the target to see who is coming and going. Briefing would involve lots of info recovered from the investigation/recon including a house layout, the surrounding terrain, photos of the target (we almost hit the wrong house once and now even use Google map print outs). Analysis after the operation often is just complaining about what went wrong/right when back at the station turning in gear.
So What about Traveller?
I don't know what you are using this information for in Traveller. I'm assuming either your players want to be in a special unit or they are scoundrels and you want some realistic and tough law to throw at them. I'll consider the second since I know what my past players have always been up to.
Breach Team
Shield: Central Supply Catalog iirc has a perfect shield for this. Laser pistol sidearm.
Ram: Something much more hi-tech. I would assume a device that can knock down a door before you even reach it.
Less Lethal: Again I think CSC has options for non-killing weapons. One or two members should be carrying such a weapon.
Medic: Carries several medkits. Laser pistol.
Team Leaders/Breachers: All armed with a Laser Carbine, Guass Carbine, or Advanced Combat Carbine.
Breach Team wears Combat Armor. Battledress is overkill for law enforcement and may be too big when entering starport buildings, a target spaceship, house, etc. If a situation warrants battledress, then the Imperial Marines probably have already been called. Conversely, if you think Combat Armor is too much, consider that before the Iraq war police SRT/Swat teams were probably better armored then the typical US infantryman.
An armored grav vehicle would be available. If needed, the highly armored but slow grav vehicle could insert the breach team right next to the target building/spacecraft. It's hover ability could be used to insert the team on top of a spacecraft or into an upper floor.
Perimeter Team
Armed with either a true sniper rifle or a laser rifle depending on range. Wear cloth armor, but with the best high-TL camouflage available (see Scoundrel supplement). Special observation equipment that can detect heat, IR, etc of people even inside buildings or grounded spacecraft. A grav drone (I again think Scoundrel has something) that can fly above or around the target to report information.
Perimeter team would not arrive in a vehicle, but sneak in on foot to surround the players hiding in their stolen free trader or hiding out in the Class C starport after a shoot out. :wink:
Hmm, perhaps I should greatly expand on this and send something to Signs & Portents?