Throughout the 1970s, thousands of cattle across the western and midwestern United States were found dead with surgically precise organ removals — reproductive organs, eyes, tongues, and soft tissue removed with what appeared to be laser-like cuts, with no blood at the scene. The FBI launched 'Operation Animal Mutilation' in 1979. Investigation found some animals had been tranquilized, treated with anti-coagulants, and marked with a chemical visible under fluorescent light — suggesting preselection. Unidentified quiet aircraft were reported near mutilation sites. Despite these anomalies, the FBI closed the case attributing the deaths to 'common predators.' Local law enforcement called it 'the greatest unsolved serial crime spree in history.' Cases continue to be reported today.