As posted elsewhere, I got arrested. I thought a little additional detail would be helpful for others.
I've learned to think of some things as potential warnings of rip offs- overly perfect looking studio pics, nothing explicit in the add, and for a certain variety of rip offs, non explicit pics. For this reason the Cop trap add looked good- it offered something specific (GFE + Extras!) and the photos, while not showing face or any tender bits, did show a real pic from a hotel room and a recognizable woman in some slinky underwear.
In retrospect the explicitness and lack of anything overly naughty or identifying were likely aspects of the police MO. Also a price too good to be true (100 for GFE) to bait the trap and get a quick response.
Also she was all business on the phone,friendly but not tired or sexy or whatever, and asked immediately what I wanted, and called back when I sounded unsure about the time. The ad was removed the next day.
They set up stings for limited times only, and so want efficient response. They are unlikely to offer 24 hour service, nor have a history of add making for one persona. Lady cops don't want to take pics of their kibbles and bits, and they don't want to show their faces. If she places adds regularly, and shows her face, and shows some real naughty skin, its likely she's no cop. no guarantees, just my experiance.
Once you go in the door, you will be arrested, no precautions will help other than not showing up. Forget the envelope or the LE check grope, they're bs. They will try to get you to verbally agree to solicit, but it doesn't need to be much- put it this way, if its enough for you to communicate with a real girl, its enough for them: 100 kisses for an island trip may be cute, but its no more protection than saying 100 dollars for anal sex. A mumbled 'sure' in response to an offer for some euphamism 'you want french?' is enough, but again, even if you zip you lip and try to bolt, you're trapped bud.
In another thread someone minimized getting arrested, probably released immediately with a court date etc. Well, YMMV, but in my jurisdiction I was locked up for 16 hours, 8 in a large filthy 'holding tank' cell and 8 in a 2 man greasy filthy stainless steel box, no window no view, 6 ft by 7 ft by 7ft high. I was offered one drink in that time, in stifling heat. I was kept cuffed for 2 hr's at the start, behind my back, and it was painful. All that just to process me and release on citation for a preliminary court appearance. Then had to get from central processing back across town to the station I was originally held in to reclaim my property, without my wallet or even shoe laces. And you don't have a right to a phone call, its a favor they might grant, so good luck if somebody or a boss is expecting you somewhere. They owe you nothing in jail, you're not a customer, you're an animal at the total mercy of the system.
Anyway, be cautious and follow you gut, and use all the caution before you show up. Just because there are a million explicit adds online doesn't mean that this is 'accepted' by society or LE.
Add on the court time, which isn't scheduled around your work schedule, and all the costs (well over a grand all told )and trying to lie all this away with my wife, and this is a very big deal, though nothing compared to hard time. Anyway, jail is worse than you think, and shouldn't be minimized.