Police crash reports are not admissible in court to prove that the accident was the other driver’s fault. They are used as a method for the state of Virginia to collect information on crashes for accident prevention purposes.
A favorable crash report can help you, because an insurance company may use it to help make a decision in your claim, and it can provide a road map for a more thorough investigation, but it cannot be used to help you if you need to go to court. The law in Virginia making crash reports inadmissible can be found here.
Because a police crash report cannot help you in court in Virginia, it is important to gather evidence yourself (or hire an attorney to do so for you). An experienced investigator may photograph a scene, collect witness statements, and take measurements before an accident scene is altered.
The insurance company is usually under no duty to share its investigatory material with you, and unless you have been to trial before, you may not know how to preserve the best evidence in your case. Early in the case is usually the best time to preserve important evidence in your case, aside from the police crash report.