The End of The World Detective. Supernatural Sleuths Series, #1

The Apocalypse May Have Happened But Crime Hasn't Gone Away The world as we know it ended when demons from another dimension invaded and butchered more than half the Earth's population. Humanity is barely surviving. And yet they find time to commit murder. The End of the World Detective: The world may have ended but that doesn't mean Agent Elric will let you get away with murder. 4 stories : This Girl Wasn't Killed by a Demon - Elric believes a dead girl was killed by humans, not demons. The Demon Didn't Rob That Bank - Did demons really rob a bank, or is sometime trying to fool the army police? The Ghost Highway To Scotland - While hunting a dangerous demon, Elric comes across a mysterious highway haunted by the dead. Jane Doe, Killed by Evil Humans - Someone used a demon attack to cover up a murder.
But before Elric can investigate, he is attacked by demons.  Part of the Supernatural Sleuths Series These detectives don't deal with normal cases. No missing cats and cheating husbands. Only demons who want to rip them apart, dead people who want to solve their own murders and gods who play with them like puppets. Books in the series: Book 1: The Defeated Detective: Royce loses every case he takes.
Also, he ends up being killed a lot and must often dig his way out of the grave before he can solve any crime. Book 2: The Mad Detective: Malk is a homeless boy who sees old horrors that shouldn't exist. And when they murder innocents in our world, he must bring the monsters to justice. If he can. Book 3: The End of The World Detective: The apocalypse may have happened but crime hasn't gone away. Elric will make sure that people don't use the apocalypse as an excuse to get away with murder.