In a car crash or other incident involving multiple vehicles the police may investigate whether the driver of any of the vehicles is under the influence of or intoxicated by alcohol or drugs, and are not limited to investigating and arresting only the driver who was at fault in the accident, for example.
In South Dakota, law enforcement officers have the authority to investigate any driver involved in a car crash or multi-vehicle incident for driving under the influence (DUI) of alcohol or drugs, regardless of who is at fault for the accident. South Dakota Codified Laws (SDCL) grant police the power to conduct field sobriety tests, breathalyzer tests, or other chemical tests if they have reasonable grounds to believe a driver is intoxicated. This means that even if a driver is not responsible for causing the accident, they can still be investigated and potentially arrested for DUI if there is probable cause to suspect they are under the influence. The state's implied consent laws require drivers to submit to such tests when lawfully requested by a police officer, and refusal to comply can result in immediate administrative penalties, including the revocation of driving privileges.