With an extensive list of published titles, Cath Staincliffe is obviously doing something right, but on the strength of Missing, which was a fairly straightforward read I don't think I'll be investigating too much further. The list below is for reference and memory jogging rather than seeking out and buying/borrowing purposes.

Read:
Missing (2007), the seventh in the Sal Kilkenny series, where the Manchester P.I. tackles three cases involving someone who has gone missing while coming to terms with an emerging relationship with her fellow single parent house mate.
A week after supply teacher Janet Florin has disappeared, Kilkenny is hired to carry out a bit of research by her best friend, Trisha Marlowe. At the same time she finds herself caught up trying to track down Iranian asylum seeker Ramin's brother, Berfan, who has flown the coop after his application was rejected and she's done most of the groundwork that might reunite musician Bob Swithinbankwith his birth mother.
Competently written and an easy read, but this one didn't spark enough interest to have the other titles added to the Chase these down list. You can't read them all, can you?

Series:
Sal Kilkenny:
Looking For Trouble (1994)
Go Not Gently (1997)
Dead Wrong (1998)
Stone Cold Red Hot (2001)
Towers of Silence (2002)
Bitter Blue (2003)
Crying Out Loud (2011)

Janine Lewis:
Blue Murder (2004)
Hit and Run (2005)

Scott & Bailey:
Dead To Me (2012)

Standalone titles:
Trio (2002)
The Kindest Thing (2009)
Witness (2011)
Split Second (2012)

Novellas
In the Heart of the City (2011)
Violation (2011)