I suggest spending some time on the newbie board and doing a search for LE Check.  This topic is very well covered there.  It is my understanding that no LE check provides any certainty to the situation.  You are always in danger of getting arrested.  Stay with well reviewed and respected ladies and you will minimize those risks.  I said minimize - you can never eliminate them.

Do you mean where the girl grabs you or you grab her?? IF so, HOW IN THE WORLD do you think that proves either one of you are LE?? I mean there are some that have gone all the way, then arrest.

Do your research, look over reviews, and then decide who you want to see based on that, instead of worrying about a stupid "LE Check

For those who don't know (which, judging from the reviews, is most) - law enforcement officers working undercover have a privilege to engage in illegal activity if necessary to apprehend criminals. Its not entrapment unless the escort can PROVE that the idea of charging for sex had not crossed her mind until the officer suggested it.

Grabbing his dick - or having him grab her - does nothing to prove that she didn't have any preconceived thoughts of prostitution.

Just as worthless as asking "are you a cop" - or the ads that say "by answering this ad you represent that you are not affiliated with law enforcement". Do people actually believe that this creates an enforceable contract?

OTOH - you asked what makes girls wary. Often - trying to explain this makes them wary. Some ladies apparently think that I'm tryin to get them to let down their guard.

So ... if its important to the lady ... I just say "grab away".

Here's the conversation that will get you busted:  "If I pay you $X will you give me Y sexual favor."

Here's the conversation you're allowed to have:  "I'd like to see you for an hour, what's your rate and when are you available?"

But, you're thinking, that would allow her to take my money and just play tiddelywinks for an hour and I'd have no verbal contract to allow me to get my money back.  Yep.  

That's where TER comes in.  Check her reviews.  Know ahead of time what she does and doesn't do.  Know who the rip-off artists are.

You and the lady are both potentially committing a crime, so you both want to dance this dance.  So if she's on the phone and says to you, "So what exactly do you want for your money?" you need to hang up or respond with "I just want someone to talk to" because only a fool or a cop is going to be that direct on the phone.

So be discreet, dance the dance, do your homework, and walk into your appointment assuming that all you and that gorgeous lady in the lace teddy are going to do is play tiddelywinks and you'll be just fine.

the TL;DR of that article is this.  If LE wants to bust you, they're not going to ask you to screen.  So, if a cop is posing as an escort, they're more likely to just give you an address and tell you to come on over without requiring any sort of screening info.  The same goes for anyone attempting to rob you, i'd imagine.  

Those that have no need to worry about their safety (ie not screening you) either have nothing to lose or a lot to gain.  Go with ladies that are well reviewed and known to have some sort of screening policy.  Nothing is guaranteed, but that should keep you fairly safe from LE.