I answered a backpage add that requested the viewer to e-mail for pics/more information. I did so and was careful to say that I was interested in becoming friends.  The provider sent me a couple of nude pics. I'm new at this, so I'm wondering if this means I'm safe from the police.  I mean, were this a sting, they wouldn't send me nude pics simply for inquiring about friendship, right?

...whose nude pix are they?  Can you say for sure??  No!  Are they the pix of the provider ???  Are the police prohibited from sending you nude pix???  Think so ???  Is it a crime to send or receive nude pix??? NO !  So all this means absolutley NOTHING !  Therefore, the question is how else have you verified the sender is for real?  Did you check a web site?  Read a review?  How many?  Have you seen anything relating to this provider on any other site, anywhere?  If not, please stop now.  Then check out providers who are well reviewed on this and other sites before chasing this kind of shit.

What she did is not unusual, but it also doesn't mean she is not LE. It could be Sargent Joe sending you pics he found somewhere else on the internet.

well said, inicky.

There are too many scams to list.  Recently discovered a lady on my bucket list...  before seeing her...  was using her pictures from several years ago.  She's no longer on my list, BTW.
It is recommended you see well reviewed ladies and you'll only know that by getting VIP and reading the reviews.  The existance of a review does not tell you what is in it!  The likelihood of a scam is larger than LE.
You really should read the self-help section, and read back on this board until you can answer every question yourself...  Not to be a PITA but you must learn this & much depends on the filter of your own circumstance & risk tollerance.
When you are ready for VIP, the cost is less than even one spoiled date.
skb