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 Illinois, 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. Illinois law, under statutes such as 625 ILCS 5/11-501, prohibits driving while under the influence of alcohol, drugs, or intoxicating compounds. If an officer has reasonable suspicion based on observable signs of impairment or erratic driving behavior, they can conduct field sobriety tests and may request a chemical test. Refusal to submit to such testing can result in statutory summary suspension of driving privileges. The law applies to all drivers, regardless of fault in the incident.