The Caves of Steel by Isaac Asimov

Elijah Baley is a detective working in New York City, in a future where Earth is over-populated and humans have colonized the sky and other planets - otherwise known as Spacers, who are looked down upon by those remaining on Earth. Androids are also becoming more and more prevalent, yet still rejected by the humans on Earth. When a member of Spacetown is found ***ed, and an Earth conspiracy group theorized to be the culprits, Baley must work with one of the dreaded Spacers. Even worse; the Spacer in questioned is R. Daneel Olivaw, who is a robot. Together, they must come together to find out who is the true ***er. This is the first novel in Isaac Asimov's Robot series.