Narrator: This is Science Today. How do developers of technology capable of detecting weapons of mass destruction, or WMDs, abide by Fourth Amendment prohibitions against unreasonable searches and seizures and the proper issuance of warrants? It's a question that's explored by Dan Prosnitz, deputy director of the Lawrence Livermore National Laboratory's Homeland Security Organization.
Prosnitz: The courts have ruled a number of cases, most of which have to do with drugs and dog sniffs or dogs that can detect drugs or explosives. If all you reveal is what's called contraband – an illegal substance, then whatever detection method you used is OK. That is, they've ruled you have no expectation of privacy in legal substances, so if we can come up with a detector that only reveals illegal substance and reveals nothing else – red, green light, then maybe that stands a better chance.Narrator: Prosnitz says scientists and engineers who are aware of limitations on search and seizure in the U.S. Constitution can help ensure that the technical community's efforts will be maximally useful. For Science Today, I'm