The way you do that is simple. 1) ABC runs the operation. 2) ABC evolves information that illegal activity is going on in the bar. 3) ABC articulates said information on a warrant application and takes it to a friendly judge. 4) After the warrant is signed, ABC teams with local agencies to conduct the raid. Normally, we'd take local police, probation and parole officers, juvenile detectives, Military Police (in case you had to process GIs), the Fire Marshall, and the Health inspector. Maybe a couple of K-9 officers.
About a half-hour before the raid, everyone meets at a rally point. You send two plainclothes officers (a male and female) in the bar to find a place and get comfortable. Pay the cover, buy a drink. At H-hour, they move to the restrooms to lock them down as the raid team goes through the door. You don't want the patrons flushing contraband, and they'll try, Lord, how they'll try.
The lead ABC officer gives the barkeep a copy of the warrant. The local police control the crowd while the probation officers look for their clientele (who ain't supposed to be there), the health inspector does his thing, the K-9s look for dope, etc, etc. You'll normally find dope hear the bandstand. And, every gal in the place suddenly has an urge to urinate. Amazing.
After you've checked everything you leave. If the bar is reasonably clean, you remind the barkeep that closing time is 2:00 a.m. If the bar is being run wrongly, the Fire Marshall and ABC in cooperation with the Health Inspector, shut it down.
And that's the way you do a bar raid. Simple, no? The last one I was on, I was on the entry team, and when we came through the door, we noticed a three-year-old sitting a the bar, drinking Pepsi from a sippy cup and coloring in a coloring book. That was a very interesting raid. We took the dope out of there in a bushel basket, and we wrote over 200 juvenile citations. In a bar raid. Very interesting night.That's the way you do a bar raid. Do the paperwork first, do the planning next, then go out and play with the criminals. You rookies write that down, it will keep you out of trouble later.