A good demonstration of the SDI 40MM non-lethal marking round as it's flight is captured until impact against a glass target. This video shows how paint is distributed upon impact just as it would on an assailant that police or security forces might be tracking with the goal of apprehension.
Once marked by the paint marking payload, authorities would be able to apprehend suspects later when the situation allows it. In many public demonstrations there are often small groups of individuals that are agitating or provoking acts of violence but due to the nature of the situation, authorities are unable to apprehend. This BIP Marking round can paint those individuals for later arrest.
