Imagine that you're driving your car, and another driver negligently crashes into and hurts you. A police officer arrives at the scene, talks to both of you, looks at the vehicles and the scene, and concludes you are right. He writes a police report that faults the other driver. Later, you make a claim against the other driver, who lies and denies he was at fault. You file a lawsuit to prove you're right. Is that police report going to help you?
Unfortunately, no. The general rule in American courts is that you cannot introduce someone else's statement - in this case, the report written by the police officer - unless the person who made it actually comes to testify in court. In other words, you have to call the police officer to personally testify to what he saw and heard. By itself, the police report won't do you any good (although it might help you investigate in preparation for trial).