conspiracy. because there's an exception to the hearsay rule. normally, a witness who doesn't have direct knowledge, not terribly good. in a conspiracy, it can be a very important witness. so the white house is brushing this off. they might be careless or just trying to play it down. i'm not sure which one. >> we've been talking about the terms that are used in law enforcement and prosecutions. but sources told cnn that gates participated in something called a queen for a day interview with mueller's prosecutors. tell us about that and what questions mueller's team was likely asking him about. >> well, that's a term that isn't used as much today. it's when a witness goes in for a proffer, or a potential target goes in for a proffer, to offer what they could give the government in exchange for a plea deal. and in those circumstances, the witness, or the target, is granted immunity, that's where the queen for the day term comes from, that was an old television or radio show, i'm not sure