Complex sentence: Some evidence at the crime scene was improperly handled by the police investigators: a trail in the dirt (from the elevator shaft) along which police believed Phagan had been dragged was trampled; the footprints were not identified.
Split into simpler sentences: Some evidence at the crime scene was improperly handled by the police investigators. A trail in the dirt (from the elevator shaft) along which police believed Phagan had been dragged was trampled; the footprints were not identified.