No one will ever know of a certain ICO if it is a scammer or a true ICO. But for me a specific ICO is real if it has a website and a Whitepaper and has a roadmap. That is the thing I consider to verify if this is not a scam.
Looking at the white paper and road map will not help to find out if the ICO is just a scam and doesn't have intention to move forward with what they are planning.
The only way to know if a project is a scam through this
Detecting early will become possible only if a crypto currency is coming from a known team of scammers.
Scammers will be scammers and if they are done with their past scam coin, they will generate a new one to scam more money.