Epstein's conviction for raping a minor was public information at the point that Joi Ito raised money from, coinvested with and visited his homes. Far more information is included in Ethan's MIT resignation post:

He should step down from the boards of the Media Lab and The New York Times. Far more information is provided in Ethan's resignation letter than in Ito's "apology":

http://www.ethanzuckerman.com/blog/2019/08/20/on-me-and-the-...

There's no way Ito didn't know about this, it would come up with a simple Google search. Investors do diligence.