Barbara Venkataraman 
Jeopardy In July [EPUB ebook] 

The fifth book in the Jamie Quinn Cozy Mysteries series leads Jamie to La Vida Boca: a posh assisted living facility in Boca Raton where old people are dying at an alarming rate.
With its sterling reputation, dedicated staff and top-notch medical care, none of the deaths are considered suspicious. But when members of the poker club start to die under strange circumstances, attorney Jamie Quinn finds herself once again embroiled in a mystery.
With help from her new friend, Jessie Sandler, and her favorite P.I., Duke Broussard, Jamie uncovers a crime that took place forty years earlier. But can she stop the killer in time, or will she become the next victim?