Complex sentence: At the hospital, she kept her blood-stained suit on but removed her hat; the whereabouts of the hat today are unknown, and the last person known to have had it--her personal secretary, Mary Gallagher--will not discuss it.
Split into simpler sentences: At the hospital, she kept her blood-stained suit on but had removed her hat. The whereabouts of the hat today are unknown, and the last person known to have had it--her personal secretary, Mary Gallagher--will not discuss it.