The echo man - Richard Montanari

In Philadelphia the mutilated body of a man is found in one of the poorest neighbourhoods of the city.
The victim has been viciously tortured to death.
It's the work of a sick mind in free fall.
Homicide detectives Kevin Byrne and Jessica Balzano investigate and soon realise that their crime scene is linked to the past.
Eight years ago, another body was found in the same place, in the same position, killed in the same manner.
That case was never closed.
Apart from their killer's unusual calling cards, the crime scene photos - past and present - are identical. As another brutalised body appears, then another, it becomes clear that someone is recreating unsolved murders from Philadelphia's past and the killer is closer than they think...