Darkness by Kate Sherwood

A murdered prostitute. An obvious suspect. Clear evidence. For once, Jericho Crewe has a straightforward crime to investigate, and Wade Granger isn’t involved.

It all seems so simple, but Jericho’s instincts won’t let him rest. As he investigates, he finds troubling suggestions that the murder is a part of something larger and more sinister. But working within the boundaries of the law may keep him from finding the truth. If Jericho doesn’t break the rules, an innocent man may rot in jail while a killer remains free to strike again.

Inevitably, it all comes back to Wade. Because who else knows as much about breaking rules? And who else knows Jericho the way Wade does—not wisely, but far, far too well?