An Ames man has been arrested in the killing of Ames female. The body of the unidentified woman was found Thursday night during a welfare check at an apartment in the 5300 block of Mortensen. Just before midnight, Oscar Chavez was arrested in Sac County and charged with first-degree murder. The name of the victim has not been released. The body was sent to the State Medical Examiner’s Office for an autopsy.