Stray Kat Waltz by Karen Kijewski Copyright 1998

From the back cover:

“Quintessential female P.I. Kat Colorado return in the newest novel from award-winning author Karen Kijewski… Kat is still reeling from the loss of her beloved Hank. But when Sara Bernard insists that her husband is trying  to kill her – a claim seemingly backed up by the murder of her best friend – Kat finally agrees to investigate. The problem is not only that Jed Bernard, a police officer, has a clean record and glowing testimonials from everyone in town. It’s also that the erratic, elusive Sara Bernard sometimes seems more dangerous than the man she’s trying to avoid. And when Kat finds herself going undercover at a stylish rehab clinic, it seems that there’s far more to this case than a marriage gone bad….