I think you can check it out from some topic in this forum or some websites on the internet such as scamadviser.com

Scamadviser isn't that reliable and I find it out that they are only trying to destroy those good casino's that has reputation. And in able to be removed to their red list, you need to pay them. And that is what they are doing, it is still better to visit to the main threads of each casino's here.
I think that they could easily do that, and it's better to use the site yourself and see how the players there are reacting. If the players are playing well and see that they are having fun and nothing is cheating them or something. The best thing that you could do is what tabas suggested, bitcointalk is a very reliable one because there are great moderators that monitor activity.