Pluto Vol 2

From the VIZ Media edition

In a distant future where sentient humanoid robots pass for human, someone or some thing is out to destroy the seven great robots of the world. Europol's top detective Gesicht is assigned to investigate these mysterious robot serial murdersùthe only catch is that he himself is one of the seven targets. Atom, a boy robot whose sophisticated AI programming seamlessly blurs the distinction between man and machine, starts his own investigation into the serial murders of the great robots of the world. When he discovers that the killer's motives may be connected with the geopolitical events of the recent past, he realizes that the case is far larger than anyone could have ever imagined.

Source: Anime News Network Encyclopedia