Twelve hours after we bought my car, out neighbor backed into it, pushing the front bumper towards the passenger side, and inwards. We didn't notice it when we left the house, but did see it later on that day. We knew if was him because of the paint tranfer.
He denied it, of course, and kept denying it even though the measurements all added up nicely.
So, I hired a forensics investigator, who came out, did his thing, and handed the guy his findings...why his paint was on my car, but mine not on his (he had no clear coat, I do) exact measurments, angle of impact, and even showed him why the bumber of his 'vete didn't shatter like he thought it would.
He still denied it, but accepted responsibility.
His insurance dropped him like a hot rock after settling...