The ID2 scanner has raised hopes among police that it will assist in controlling the growing methamphetamine traffic problem, but it has raised eyebrows elsewhere, particularly in some legal circles. Some legal experts believe the scanner must first be independently tested and validated before a court can legitimately admit scanner results into evidence.
"Independent testing by outside experts likely will come the first time a prosecutor takes scanner-derived evidence into court," Philips says.
There are other legal gray areas surrounding the scanner.
Suppose a meth scanner used by a police officer on a routine traffic stop detects methamphetamine on a car door. Does this meet the standard of evidence being in plain view? Does use of the device constitute a search? Does its use violate Fourth Amendment protections against unreasonable search and seizure?
"It's not entirely clear how the courts will treat the use of the scanner device," says Greggory Nojiem, staff counsel at the Center for Democracy and Technology. "As new search technologies come to market, the courts and Congress will have to decide how to protect that zone of privacy [that] Americans prize."
The U.S. Supreme Court has ruled that police must have a search warrant before they can use a thermal-imaging device to detect the presence of marijuana growing inside a private home. Yet, in US v. Place, the U.S. Supreme Court held that a sniff by a narcotic detection dog of closed luggage was not a search because it could disclose only whether the luggage contained contraband.
Will police likewise need a search warrant to perform a meth scan of the interior of a private vehicle during a traffic stop? Will scanning the clothing of concert-goers entering an arena be considered legitimate, or do concert goers have an expectation of privacy?
In Illinois v. Caballes, the U.S. Supreme Court held that a dog sniff does not violate the Fourth Amendment if it occurs during the course of an otherwise valid traffic stop as long as it does not extend the duration or intrusiveness of the stop.
"This scanner technology appears to function as the sniffer dog — it can disclose only the presence of contraband," says Lawrence Rosenthal, a law professor at the Chapman University School of Law. "Accordingly, as long as the use of this technology does not extend the duration or intrusiveness of a traffic stop, I do not believe that it would run afoul of the Fourth Amendment."
Douglas Page writes about science, technology and medicine from Pine Mountain, Calif. He can be reached at firstname.lastname@example.org.