Dying Games — Steve Robinson

Washington, DC: Twin brothers are found drowned in a Perspex box, one gagged and strapped to a chair. It's the latest in a series of cruel and elaborate murders with two things in common: the killer has left a family history chart at each crime scene, and the victims all have a connection to genealogical sleuth Jefferson Tayte.

Hoping his insight and expertise will help solve the case, the FBI summon Tayte back to the capital. But as he struggles to crack the clues, the killer strikes again -- and again. Tayte is known as the best in the business, but this time he's up against a genealogical mastermind who always seems to be one step ahead.

With the clock ticking and the body count rising, Tayte finds himself racked with guilt, his reputation and career in tatters. The killer is running rings around him; is it only a matter of time before he comes for the ultimate target?

This is the sixth book in the Jefferson Tayte Genealogical Mystery series but can be enjoyed as a stand-alone story.