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 Missouri, when a car crash or other incident involving multiple vehicles occurs, law enforcement officers have the authority to investigate all drivers involved for potential impairment due to alcohol or drugs. This means that even if a driver is not at fault for the accident, they can still be subject to investigation and arrest if there is probable cause to believe they are under the influence. Missouri law, under Revised Statutes of Missouri (RSMo), allows officers to conduct field sobriety tests and use breathalyzers or other chemical tests to determine a driver's level of intoxication. If a driver is found to be driving while intoxicated (DWI), they can face charges regardless of their role in the accident. The state's implied consent law requires drivers to submit to alcohol or drug testing if arrested for DWI, and refusal to do so can result in license revocation and other penalties.