Simon Kernick - The Business of Dying

This is the third one by this author I have read. I enjoyed the first one 'Relentless' but was disappointed with the second one I read 'Target', so I dubiously picked this one up in a second hand book shop but it turned out a good choice. This was actually Simon Kernicks first book.
The main character is DS Dennis Milne, a London Met copper who is more bent than a waste pipe. Being disillusioned with the UK criminal justice system, seeing the pervs getting off on a 'technicality' he decided to take the law into his own hands and take these low life's off the streets for good. The police don't normally spend a lot of working hours looking for the perpetrators of these crimes, as they consider society better off without them anyway!
Unfortunately, it's getting out of hand, DS Milne is being paid to rid the streets of the scum by Raymond Keen, a business man whose main business is the wrong side of the law.
One cold, November night, in a pub carpark, DS Milne is waiting to kill 3 men. But three men go drastically wrong after the shooting. First he is seen by a female worker at the pub who can later give a good description to investigators. Secondly, he is stopped and questioned at a police roadblock near the scene of the crime. Thirdly, he was set up. The men he shot were 2 customs men and an accountant. This is one crime that will not go away and DS Milne is becoming a prime suspect but the CBI have no evidence yet but they are keeping him under surveillance.
DS Milne was investigating the murders of 2 teenage girls who he believes were linked to an organised sick paedo/pervi ring. Although he will soon have to go on the run he wants to put these sick people away. And so the hunter becomes the hunted by both colleagues and enemies.
I enjoyed this book, it's up with his best. It's a disturbing but gripping read.
I'm not sure what I think/feel about DS Milne. If he were exterminating child molesters/killers, drug barons, pimps and human traffickers without being paid to do it he would probably be a hero but he isn't; he is getting paid to be a hitman by someone who themselves works on the wrong side of the law.
Do I like him? I don't know.........