Complex sentence: Ellie Burr (Hilary Swank), a young police officer and Dormer's biggest fan, is put in charge of the investigation into Eckhart's shooting, which causes Dormer to use his influence and reputation to try and mislead her into believing the suspect killed Eckhart.
Split into simpler sentences: Ellie Burr (Hilary Swank), a young police officer and Dormer's biggest fan, is put in charge of the investigation of Eckhart's shooting. Dormer uses his influence and reputation to try and mislead her into believing the suspect killed Eckhart.