In alleged DUI cases that involve serious accidents, the police are often not able to perform their usual DUI investigations which include field sobriety tests and a breathalyzer test, if the suspect consents to them. If the suspect is in no condition to perform those tests due to injuries from the crash or is taken to the hospital, the police cannot perform the normal DUI investigation. If the police are able to develop probable cause that the suspect was driving while impaired from alcohol or drugs, there are ways for the police to continue investigating a DUI after a crash.
The police officer can go to the hospital and request that the driver submit to a blood draw. After the blood is taken from the DUI suspect, the police send it to the crime lab where it is tested for drug and alcohol content.
However, as a result of a United States Supreme Court case that was decided in 2013, the police cannot take a DUI suspect’s blood without consent from the suspect or a search warrant. The state used to be able to argue that they did not need a search warrant due to exigent circumstances inherent in a DUI case- that alcohol is constantly metabolizing in the blood and as time passes, getting an accurate blood alcohol reading becomes more difficult. The recent Supreme Court case rejected that argument. The general rule is that a blood draw is considered a search under the Constitution so the police need consent or a search warrant to obtain someone’s blood.