A Durham County jail detainee who was found unresponsive in his cell and later died was identified Monday as 37-year-old Robert Harris Jr. Harris had a Durham address and was taken from the jail Friday evening to a local hospital, where he died His death is being investigated by the State Bureau of Investigation and the Durham County Sheriff’s Office, which is standard when an inmate dies. The N.C. Office of the Medical Examiner will conduct an autopsy, which is also standard.