“His neighbors really don’t have anything to steal, and most are of the same sort as he (and my niece.)”
Sounds like an interesting place; sorry your niece is involved.
The answer is: millions of people choose these things, and re-choose them every single day. My niece is a junkie. She has chosen to be a junkie, and she re-chooses to be a junkie every day. This is the nature of evil.
If prayer could help her, she would have been clean long ago.