It may have cost $3.5 billion over seven years. And it may not function so well in the blistering summer heat. But when 475 Afghan prisoners tunnelled out of the Saraposa jail in Kandahar, the U.S. military’s biometrics program helped round them back up.

Within days, the New York Times marvels, about 35 escapees from Sarapova got picked up at checkpoints, border crossings and even a recruiting station for Afghan security forces.  That’s thanks to the distribution of iris scans, fingerprints, and facial data that taken from inmates in Afghan prisons and sent to handheld devices wielded by U.S. and Afghan forces.

OK, so that’s only about 7 percent of Sarposa’s former residents, after the Taliban claimed a massive propaganda victory with the jailbreak. But given the difficulties of picking a face out of a crowd at a checkpoint or the ease with which people can forge ID papers, any irrefutable evidence that can mitigate the jailbreak is surely a relief to U.S. forces.

Especially since those forces have been huge boosters of collecting biometric data. The Detention Facility at Parwan, Afghanistan’s largest battlefield prison, isn’t just a jail. It’s a datafarm, too. Detainees who enter have their “unique identifiers” — eyes, fingerprints rolled nearly 360 degrees — collected by intimidating machines and scanned into something called the Automated Biometric Information System.

That database is accessible to troops out on patrol or manning checkpoints through handheld devices called the Biometric Automated Toolset, called BAT or BATS. The lightweight toolkits troops check Afghans’ biometrics against those of known detainees. A component called a Handheld Interagency Identity Detection System (HIIDE) performs the same biometric scans on people nabbed during field operations before they’re taken to detention centers, and feeds back into the Automated Biometric Information System. (I once saw it in action against a suspected Talib in eastern Afghanistan who was dressed in women’s clothing.)

Danger Room has covered all aspects of the military’s love affair with biometrics over the years, which started in Iraq. The idea is to create a foolproof (or near foolproof) way of distinguishing insurgents — or at least detainees — from civilian noncombatants. The U.S. envisions a database consisting of millions of Afghans’ unique physical characteristics, all to turn over to the Afghans. The Times reports the database consists of 1.5 million Afghans thus far.

Special Operations Forces have a head start. For years, as they’ve hunted terrorists, they’ve used something called a Secure Electronic Enrollment Kit, which takes much the same scans as a HIIDE and sends it back to an FBI lab in West Virginia.

Biometrics are no panacea. Passively waiting for suspicious persons to arrive at a checkpoint for scanning isn’t a sound forensic technique. The potential for abuse is vast. And the heat of Afghanistan can turn the handheld scanners tetchy. But so far, the Times reports, the biometrics program has garnered “only occasional complaints” from Afghans. Maybe they’re seek of being falsely accused of being insurgents by people who don’t speak their language.

Photo: U.S. Air Force