Apidae. Andi Hayes Detective Series, #3

No good deed - or good record of solving crimes - goes unpunished. Detectives Andi Hayes and George Donovan of the Charleston PD are on vacation. Or at least they are until they are called back for an emergency: find Chief Norris's missing son. Fortunately, Andi's insect spies lead him right to young Tyler Norris, who is safe and sound. Unfortunately, along with the chief's son, they find twenty-five corpses, victims of a serial killer who has gone unnoticed for over a decade.
Chief Norris promptly cancels Andi and George's vacation and assigns them as lead detectives on the case. Physical evidence leads them to a mental health facility where some of the victims received treatment, but Andi's geschenk - his usual secret weapon- fails him. Promising leads and shady suspects all turn out to be dead ends, and they're running out of time. Because the killer isn't going to stop at twenty-five victims - and Tyler Norris has just gone missing again .