Shell asked for recs, and I was just thinking about this series the other day. It's a crossover between HCL and DaVinci's Inquest, both of which had CKR characters. No, the pairing isn't the two CKR characters, don't panic. But the Billy is very rough-edged and kind of a bastard ... and it really works well.
If you haven't seen DaVinci's Inquest yet, let me fill you in a tiny bit (my knowledge is sadly limited, I need to beg more tapes from Betty or someone). Cal plays a detective named Bobby Marlow -- he's assigned to Sex Crimes, and gets involved with the Coroner's Office (and DaVinci, played by Nicholas Cambell(mmmmm)) on a homicide case when his girlfriend turns up dead. It's a very well-written show, IMO, and if A&E or Bravo were to start airing it, I'd be overjoyed.
The crossover set-up is that Bobby and Billy are cousins, and they have some interesting interaction that really rings true for each character.
It's a good long read if you go through the whole thing, so enjoy!
Lost Horizons