Pima County Sheriff's Deputy Jason Ogan said Sunday that the man was a cab driver who drove the gunman to the grocery store outside of which the shooting occurred.
Ogan says the man went into the store because the gunman apparently hadn't paid his fare.
Authorities had been seeking the man as a suspected accomplice because he was captured on security cameras near the gunman and at the scene Saturday.
Ogan says the cab driver "came by, and we talked to him and we determined he was not involved."
He also says authorities were not ready to say if they are confident the gunman acted alone.
