Midnight Guardians — Jonathon King

When private eye Max Freeman is hired to investigate a conspiracy involving fake claims to Medicare, he quickly realizes the scheme is much more dangerous than anyone assumed. And when the Brown Man, a former drug kingpin who once helped Max catch a serial killer, reappears in a slick new guise, Max must reclaim his street instincts, to protect not just the citizens of South Florida, but also his girlfriend, Detective Sherry Richards...