A book in which a character uses an alias

[Stina]

I don't think it's a spoiler to tell you that I counted Killer Chardonnay for this. Remember, people can have all sorts of reasons for using aliases. I have lost count of mine, and I swear, I have never murdered anybody. (Every time I say that, I find myself surprised. I have to think about it for a minute to make sure I have, in fact, never killed anybody and it just slipped my mind.)

[Cheryl]

I think I will count The Tell-Tale Start here, because the villain uses a false name