"His entire family was by his bedside when he passed," the family's attorney, Mike Manning, said. His parents, two brothers and three sons were there to make the decision.
Atencio had been taken to St. Joseph's Hospital and Medical Center in critical condition with injuries from the fight. Doctors later determined he had been shocked at least four times with a Taser, according to Manning.
Earlier on Tuesday, Manning said Atencio was brain dead and his family had flown to Phoenix to decide whether to take him off life support.
Phoenix police arrested Atencio after he was seen kicking on the door of an apartment and then harassing a woman walking down the street. Manning said Atencio suffered from bipolar disorder and had been off his medication.
Phoenix officers processed him and took him to the Maricopa County jail for holding. At the jail, however, Atencio began struggling with officers from both Phoenix and Maricopa County law enforcement, according to statements by both agencies.
Neither agency has detailed exactly what happened during the struggle. The sheriff's office has yet to release a video of the incident to Phoenix police, Atencio's family or the public.