Can border agents search a gas tank?

This has not been an encouraging year at the US Supreme Court for those advocating the privacy rights of passengers and drivers in motor vehicles.

The justices ruled 9 to 0 in December that police are justified in arresting everyone in a car when narcotics are discovered and no one admits to ownership of the drugs. And in a 6-3 ruling last month, the high court endorsed police use of random roadblocks to help locate witnesses to an unsolved hit and run accident.

Wednesday, the justices are set to hear arguments in yet another case involving a driver claiming Fourth Amendment protections. At issue in US v. Manuel Flores-Montano is whether agents manning a US border station may order the disassembly of a gas tank even when the agents do not have reasonable suspicion to believe it contains contraband.

From the government's perspective, the case is important because the ability to conduct such suspicionless searches helps create a deterrent among would-be smugglers - including, in theory, terrorists armed with a weapon of mass destruction. From the perspective of civil libertarians, such tactics are the thin edge of a wedge that could lead to increasingly intrusive searches of all types at border crossings and airports.

"This is the functional equivalent of a strip search or a body cavity search for a car," says Tracy Maclin, a Fourth Amendment scholar at Boston University School of Law. "Some people say that is no big deal, but it lends itself to other applications."

The Supreme Court has ruled that US border officials may conduct suspicionless searches of the luggage of arriving passengers, but may not conduct a strip search or body cavity search without reasonable suspicion that they are involved in a crime. "If the government has this authority with respect to cars why can't they do it with respect to other effects," Mr. Maclin says.

The case before the court began in Feb. 2002 when Manuel Flores-Montano drove his 1987 Ford Taurus station wagon from Mexico into the Otay Mesa border station in southern California.

A Customs inspector noticed Mr. Flores-Montano avoided eye contact and that his hands were shaking as he produced his US green card and driver's license. The inspector tapped on the car's fuel tank and noticed it sounded solid. In addition, a narcotics detecting dog alerted officials to the presence of drugs in the car.

The customs inspector then directed Mr. Flores-Montano to an area for secondary inspection. A mechanic removed the fuel tank and discovered 37 kilograms of plastic-wrapped bricks of marijuana.

After being indicted for drug smuggling, Flores-Montano attacked the government's actions, saying the removal of a gas tank without reasonable suspicion went beyond the kind of "routine" border search approved by the courts. A federal judge and the Ninth US Circuit Court of Appeals agreed with Flores-Montano.

At issue before the Supreme Court is whether removal of a gas tank is so "routine" that there is no need under the Fourth Amendment for agents to first possess reasonable suspicion.

"A gas tank search falls within the category of a routine search because it involves no extraordinary level of intrusion," writes US Solicitor General Theodore Olson in his brief to the court.

"The government has an overriding interest in maintaining territorial integrity at the international border," Mr. Olson says. That interest includes the need to prevent entry of "contraband, illegal aliens, communicable diseases, harmful substances, and instruments of terrorism."

Lawyers for Flores-Montano offer a different view. "While it is true that the government has wide powers of search and seizure at the border, those powers are not unlimited," says Steven Hubachek of Federal Defenders of San Diego, in his brief to the court.

"The solicitor general argues that any person who returns to the United States in a vehicle risks disassembly of that vehicle at the unfettered discretion of a low-level Customs or Immigration inspector," Mr. Hubachek says. "Disassembly of a motor vehicle for no reason whatsoever, even at the border, is not 'reasonable' under the Fourth Amendment."

Maclin says given the heightened security concerns since Sept. 11, the key issue in the case is likely to be the government's power at the border, rather than a driver's expectation of privacy.

"It is a border issue," he says. "Will 9/11 be in the back of the minds of some of the justices? I think so," Maclin says.