Scammers are easy to find out. First of all they try by all means to hide their true identities. But there are a few things that will always appear sketchy for Scam ICOs;

1. Their whitepaper at most will not by clear or rather the English will not be good as they often do their things in an abrupt way, though some now tend to be more organised.
2. If you do background checks of the teams behind the project as will be listed on the website or their whitepaper, most of them use fake identities or to some extent fictitious characters.
3. They do not often stick to their laid our road map.
4. You will often realize after they run away with your investment