First degree murder charges have been filed against a Rock Island woman and her boyfriend for the death of a four-month old infant. An autopsy conducted this week indicated that Elias Austin died of blunt force trauma to the skull. The autopsy revealed other significant injuries as well. His mother, 23 year old Tanda Allee and her boyfriend, 20 year Mateo Williams were arrested Friday and are being held in the Rock Island County Jail on $2-million bond. The investigation began on Tuesday morning when Rock Island Police responded to the 400 block of 12th Avenue in reference to an assist ambulance call for a non-responsive infant.