The process of genocide consists of a series of events which unfold according to a specific form with identifiable phases, and features a certain characteristic internal logic.
The process of genocide progresses from its beginning through a structured course to its end. First, it must define a target group (these victims usually are chosen solely on the basis that they belong to a specific group or category) and designate them for persecution or destruction. Second, the property of the members of that group must be expropriated. Third, the group must be concentrated in a single area. Fourth, the group must be deported. Finally, a significant number of the group must be killed. Although in reality these phases may unfold rapidly one after another, depending on the circumstances, it has been observed that the first phases of the process of persecution can occur in full view of the public, while later phases in most cases are shrouded in secrecy.
(Ton Zwaan "On the Etiology and Genesis of Genocides and Mass Crimes Targeting Specific Groups")