Hmmm. I'd recommend Christopher Brookmyre, who does crime meets political satire - might not be what she's after, but they're bloody good reading. Boiling A Frog is my favourite.
Michael Connolly does a good line of private detective novels with his Harry Bosch series, but his book The Poet is a good standalone one about a serial killer.
You could also do Lee Childs' Jack Reacher novels. More adventure than crime, but a nice easy page turner of a read.
James Ellroy's LA trilogy is excellent too, you probably have seen LA Confidential. That is based on part of the series.
And finally Christopher Fowler, started off as a horror writer, but has a series about a pair of detectives called Bryant & May, very eccentric very British stories about very strange crimes. Great fun series, would make a very good tv series actually. But they must be read in order, because each book follows on from the previous, giving away plot details, even though they are standalone mysteries.