In his two decades in the U.S. House of Representatives, former general counsel Kerry Kircher has seen congressional and independent counsel investigations come and go. His former deputy counsel, William Pittard of KaiserDillon, has experienced his fair share as well.

But both veteran Washington lawyers concede they have never seen anything quite like the Trump-Russia-Comey affair unfolding in the nation’s capital.

As House and U.S. Senate committees, and now special counsel Robert Mueller III, investigate any Russian involvement in the presidential election and any connection to the Trump presidential campaign itself, Kircher and Pittard predict the public will likely see a host of legal issues—including the Fifth Amendment right against self-incrimination, assertions of executive privilege and perhaps even immunized testimony.

We reached out to Kircher and Pittard this week to get their thoughts on possible legal fights that could unfold in a process that history shows will take months, if not years, to resolve. Excerpts from the separate conversation, edited for length and clarity, appear below.

Will the special counsel’s investigation have an impact on congressional investigations?

William Pittard: I think it probably complicates their investigation in the sense that witnesses are likely to be particularly reluctant to produce documents and testify. And, they’re particularly likely to make noises about invoking their Fifth Amendment right to stay silent.

That’s something each of these witnesses could have done anyway, despite a special prosecutor, but with knowledge that a special prosecutor is out there looking at this area, it makes it all the more likely lawyers will advise them to be cautious, to assert the Fifth Amendment rather than answer questions.