It may well be drunk driving laws.

Jacob Sullum has the scoop on a troubling recent ruling from the Michigan Supreme Court, which let stand a DUI conviction of a motorist who had traces of marijuana in his system leftover from smoking the drug days earlier. He obviously wasn’t impaired — the substance still in his system wasn’t psychoactive. But Bush administration drug policy people would like to see the policy expanded across the country.

Interestingly enough, Michigan is one of just a handful of states in the country that doesn’t permit roadside sobriety checkpoints. The irony is, it was a Michigan case — 1990′s Michigan v. Sitz — that led the U.S. Supreme Court to determine (in an opinion written by Rehnquist) that though roadblocks are indeed a violation of the Fourth Amendment, they aren’t enough of a violation to offset the “25,000 deaths” caused each year by drunk drivers (love those activist conservative judges and their balancing tests!).

That 25,000 figure was of course the usual “alcohol-related” nonsense pushed by temperance types (the number of fatalities caused by actual drunk drivers is closer to 5,000).

But after that ruling, the case went back to the Michigan State Supreme Court, which then determined that roadblocks are still a violation of the state’s constitution. So the state that paved the way to those annoying checkpoints doesn’t actually allow them within its own borders.

So if the federal government gets its way, might we see the day when roadkblocks are used to test motorists for remnants of marijuana smoked days ago, as per the recent Michigan case? Should technology make such tests easily applicable, it’s certainly possible (onsite blood urine tests would probably present some logistical problems).

In the 2000 case Indianapolis v. Edmond, the U.S. Supreme Court ruled that random roadblocks set up to search for illicit drugs were not constitutional. But the roadblocks in that case were set up to search for contraband, not to test drivers for drug-related impairment. I’d guess that if a state were to set up roadblocks to test motorists for drug-impaired driving, and if state officials argued that such measures were in the interest of public safety, the current Court has enough justices hostile to the Fourth Amendment to let it happen.

Even if Michigan’s position that traces of non-psychoactive compounds from marijuana found in the system days later are evidence of driving under the influence were rejected, a state could probably get away with arguing that while its roadblocks are intended to catch motorists currently impaired, motorists incidentally caught with traces marijuana in their systems from days or weeks prior are, naturally, still breaking the law, and so could legally be arrested and charged. Today, for example, roadblocks set up for the purpose of catching seatbelt or registration sticker violations wouldn’t be constitutional. But most roadblocks set up under the guise of catching drunk drivers have resulted in tickets for all sorts of unrelated minor infractions, with few if any actual drunk driving arrests. Courts don’t invalidate those tickets. So it’s difficult to see why they’d invalidate a conviction for marijuana found in a driver’s system days after ingestion, despite there being no scientific basis to argue impairment.

This entry was posted on Thursday, June 29th, 2006 at 6:56 pm by Radley Balko and is filed under Alcohol, Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.