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This is what my father does for a living. Or did until he retired earlier this year.
He is usually employed by insurance companies, uses all sorts of data sources, including crash damage, pedestrian injuries, skid marks, weather conditions, etc. He then prepares a report and acts as an expert witness in court.
His PhD was on the assessment of crash mechanics by analysis of pedestrian injury patterns.
I suppose a good crash investigator could probably make a case out of that, yes. Likewise for skid marks etc. or witness statements. However, when nobody gets injured, police involvement is usually quite limited and they'll leave the insurers to deal with it, e.g. the insurer's or insurers' own crash/claim investigator(s). (I don't know how any of that works, though.)