Nervous water / William G. Tapply.

Enhanced descriptions from Syndetics:

In one of the finest novels yet in Tapply's long-running series, Nervous Water explores the previously hidden past of his much beloved character, Boston attorney Brady Coyne. Contacted by an aged relative with whom he'd long lost touch, Brady agrees to help his Uncle Moze with a sensitive family matter. Having received a diagnosis of terminal cancer, Moze is looking to mend fences with his only daughter. But the daughter seems to have simply disappeared, leaving no clues or hints as to her whereabouts. As Brady tackles the seemingly impossible task of finding his cousin - a case that looks less and less like a simple missing person case - it becomes clear that whatever is going on now is related to a dark, undiscussed episode in his family's past: the brutal, still unsolved murder of another of Brady's uncles.