Auto Insurance Claims: Somedody crashed my car and not telling, insurance company, fist

Question
I let my boyfriend's sister borrow my car for 4 days. When she brought it back, it was dropped off before I got home. When I went to drive it I noticed it was in an accident. I went through the car a found another man's information (fist, last name, vin # make, model, yr of car, etc# which looked like the 2 parties exchanged insurance information. Now I spoke to the lady who borrowed my car and she is denied getting into an accident, and now blames her brother#messy right?!# Anyway I'm wondering since I have the guys info who was hit, how can I find out abut the accident #his # wasn't written down)Can his info be ran to locate him. I'm sure he has the answers I'm looking for. Is this going to come back on me, since I'm the registered owner???

Answer
You need to report this information to your insurance company immediately.  They will investigate and determine what needs to happen.  This is critical because it is possible the woman driving your car caused the accident.  If so, you need your insurance company to defend you from any claims brought against you as the owner.  If you do not report to them, it could jeopardize your coverage.