Crowe is willing to serve as Naz's lawyer for nothing, an offer that of course appeals to Naz's parents and Jack can't beat. Why is Crowe willing to do this? Presumably for publicity, and in bringing her into the story in this way, The Night Of takes a shot at Gloria Allred.
Though it's more complicated than that. In real life, although Allred likes publicity, she also does a lot of good for her clients and the world. We haven't yet seen Crowe in action, but there's no reason to suppose that she won't be able to do the same.
But not if Jack has anything to do about that, even though his course from now on is unclear. He still doesn't know for sure if Naz is guilty or innocent - just as we the audience don't yet know - but he increasingly wants to devote his all to doing the best that can be done for Naz. He's not about to take Crowe taking over with a deferential bow, and it will be fun to see how he strikes back.
Meanwhile, speaking of celebrity, is that what's motivating Freddy to take Naz under his wing inside prison? Hard to say, but it's always good to Michael Kenneth Williams in any role on television.
We have five more episodes to go in this mini-series, and so far, as far as we know, we haven't met any other suspects. If the killer is not Naz - which I can't believe it is - will the real killer be (a) revealed in the final episode, (b) sometime sooner, or (c) never at all?
Your guess is as good as mine, and I'll keep watching for a hint of an answer in this fine little series.
See also The Day After The Night Of on HBO