Imho it will be pretty hard (or even impossible) to prove that devs don't care about the project. They will just say hat something went wrong, they were scammed, ddossed or something else. All ICOs are not regulated, that means that you are not realy investing in the project but investing in the idea of the project that was described at the whitepaper. I don't think that police will do something while developers are at least trying to work on the project.
I would just recommend to remember all team members and make your desicion at peast partly on their trust history.