Last Spaceship to Brooklyn

It's 1952: Harry Truman is president and aliens rule the world. Operative Mingus Oughatlou is not your average New York City cop with gills. He’s a stranger in a strange land: an outcast among his own people, sent to Earth to serve the will of the Srreyan empire. While investigating a murder of one of his own race, Mingus is torn between two worlds: To find the killer he must work with his own people who scorn him to find the humans who wish to kill all Srreyans on earth. But not only is he searching for the killer of one of his own kind - he's on a quest for his own identity in a world where no one wants him. Mingus isn't sure he has what it takes to find the killer while fighting his own people's prejudice. He's not even sure how to thwart the insurgents before they overthrow the Srreyan Empire. But the real question is: does he even want to?