Fox keeps repeating Cohen testified the SDNY is investigating Trump. He did no such thing. He said in a vague way that SDNY is investigating the Trump organization, or some matters resulting from a raid on Cohen’s materials. He never said they are investigating DJT.
If Cohen has documents showing that Trump engaged in illegal activities then he violated his duties to the bar, at a minimum to withdraw from representing Trump on any matter whatsoever. in fact he had a positive duty to report such wrongdoing.