If I had to guess, I would guess that some sort of choke was used.
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Source: Martial-arts move used on man, 33, who died after alleged robbery attempt on Staten Island
Police have not charged two 29-year-old men who fended off the alleged robbery attempt.
During the course of the attempted robbery, the two victims, both 29, did some type of martial-arts move to knock the gun away and physically subdue the 33-year-old until cops arrived, according to a source with knowledge of the investigation. The suspected robber, who stood around 6 feet tall and was very thin, somehow lost consciousness, the source said.
He was pronounced dead at Staten Island University Hospital in Ocean Breeze, the police spokesman said.