I used to hunt and dig privies in the ghetto quite a bit, and I had lots of problems doing it. I was always minding my own business and the trouble would happen unexpectedly. On a number of occasions it was extremely dangerous and got very hairy. You cannot count on other people in the community to intervene or call the police if you get into trouble, you will be on your own.
None of that is guaranteed to happen if you go there once, or a couple of times. If you keep doing it you will wind up with lots of war stories so long as you do not get shot.
I lived and I learned a lot about myself in the process. I found out that I was fortunate to have a God given gift for defeating evil men, but like I said earlier- it was very dangerous and hairy. You should know how to fight, and I am not talking about boxing. The people you will encounter are ignorant, violent, aggressive, resentful, selfish, and you should never trust anyone or anything while you are out there attracting attention with your metal detector.
I did find lots of good trade tokens, and lots of nice soda pop bottles from the 1880s and 1890s, which is why I was there. If you do go, Godspeed and good luck! Never let them get you on the ground, and go after the ring leaders first.