If the police were called to the scene of a car crash where one of the victims fell asleep at the wheel and was subsequently killed, would they check the body for substances that might cause the drowsiness? In this case it would be sleeping pills. Would they treat such a case as suspicious or a simple accident?
Within the US, traffic accident investigation varies according to each state's laws. Here in California, if a death is involved, extensive evaluation of the accident scene and toxicology reports on drivers (live or dead) are required. Our California Highway Patrol even has a special investigative division dedicated to accident assessment. There is no "simple" accident when death occurs and insurance company liability is big money.
Most states mandate an autopsy for a death that takes place outside of a hospital or not under a doctor's direct care. The level of detail is NOT mandated by law, so the examiner could determine the cause of death based on a superficial examination. In your scenario, they would probably do a standard tox screen for drugs or alcohol as a matter of course.
first of all, if the driver fell asleep, how could those investigating the crash know that, unless there was a passenger who survived?... and if there was, the passenger wouldn't have just let the driver stay asleep! in most cases, a full autopsy would be done on both drivers, to determine the cause of death, since other cars/victims were involved... without doing so, it would be hard, if not impossible, to determine who and what caused the collision... if nothing else, the dueling insurance companies would insist on it, before paying any claims...
Oops, I forgot about this thread. That's not a good answer for my purposes. Anyhow, if the results of a autopsy showed that the dead person had taken sleeping pills briefly before driving, would this be treated as suspicious, a self-caused death, or an accident? The protagonist of my novel spikes said character's drink with soluble sleeping pills (only intending to take the victim out of action, but accidently killing him instead) and I'm interested in how likely the police/forensics would be to suspect the protagonist if they had no previous evidence of crimes of his behalf. How long would it be until forensic results were returned? The car swerving crazily across the road would probably be a bit of a heavy hint, I think. And there'd likely be a number of witnesses/cameras that could capture the accident, maybe with a view through the windscreen shortly before the swerve.
Well, it'd be treated as reckless and/or stupid either way, which would probably lead to more investigation. ... and this is why the investigation would take place to determine if a scenario like this had taken place. Now, I'm no expert on sleeping pills but I can't see them having a "lights out" instant effect. They would first cause drowsiness or wooziness at least. A responsable driver who hadn't been drinking as well, would likely stop in this scenario, unwilling to endanger themselves or their passengers. If you believe CSI then in an couple of hours! More likely this would take longer as the case would not be a priority in the short term unless those in the crash were famous / or national security interest / involved with another case.
