We come across many scratches on motor vehicles in accident cases. We in forensic reports just say whether the scratch was fresh or old based on oxide formation or deposition of dust . Is there any scientific method to calculate age of such scratches in hours, days,weeks and months for giving precise evidence to the court.
Outside of actually witnessing the event, I have never seen anything that could accurately identify the age of a scratch on a vehicle. There's just too many variations of environmental and climate factors affecting the results.
There are ways to develop a timeline though, including by the evidence transferred in the initial contact creating the damage (as well as the dynamics of the damage itself), but again environmental/climate influences still come into play.
Actually it is not at all possible to find the absolute age of a scratch. This is the biggest problem almost in all areas of forensic science. To determine absolute age of a scratch is not possible similarly.There are lot of weather effects and the position of the oxide on the metals.. We can just say it is fresh or old depending on the sheen present or from the underneath exposure of metal sheet. shine.