The victims weren't aware that Diakos Manolis, 19, had revenge in mind for a prior incident when he approached them and began walking with them near Bergenwood Road, Police Chief Martin Kahn said.
Manolis was joined by Luis Christian Abreu, 18, who suddenly came up from behind, he said.
Manolis and Abreu then began punching and kicking the victims, he said.
The assault became a robbery when the pair took a baseball cap worth $50 and a bluetooth speaker valued at $200 from the victims, Kahn said.
During the investigation, borough police connected Abreu to another robbery days earlier on Anderson Avenue near his home on Delano Place, the chief said.
Abreu was charged with two counts of robbery and Manolis with one. Both also were charged with employing a juvenile in their scheme.
Both were taken to the Bergen County Jail before being ordered released by a judge, pending further court action, under New Jersey's 2017 bail reform law.
Additional charges were expected.
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