not as a lawyer but as an investigator. he was working on it while giuliani was working as a personal lawyer on those efforts. kerik's cooperation means somebody who was on that team is going to be producing records and answering questions. very importantly, trump himself said today he's fine with kerik cooperating. one plot twist to keep in mind is that trump and kerik signalled that kerik wants to testify publicly. that would be quite a show if that were to happen. i don't think the committee wants that to happen. the next big question the committee has to sort out is does kerik sit for an interview if there are not tv cameras covering the entire thing. but we do know he will be producing documents.