The United States is compiling digital dossiers of the irises, fingerprints, faces and voices of terrorism suspects and using the information to track their movements and screen foreigners trying to enter the country.

Since January, military and intelligence operatives have collected the identifying data on prisoners in Afghanistan and at the U.S. naval base in Guantanamo Bay, Cuba. There are also plans to extend the collection process to Iraq in the event of a U.S. invasion.

With this project, the U.S. government has taken biometrics -- the measuring of human features -- well beyond its most common use to date: verifying people's identities before giving them access to computers or secure areas.

"We're trying to collect every biometric on every bad guy that we can," said Lt. Col. Kathy De Bolt, deputy director of the Army battle lab at Fort Huachuca, Ariz., where the biometric tools being used were developed.

"Any place we go into -- Iraq or wherever -- we're going to start building a dossier on people of interest to intelligence. Even if they get released, we have face and voice clips. When they come into one of our checkpoints, we can say, 'You're this bad guy from here.'"

Identified by iris

In biometrics, optical, thermal and audio scanners are used to record a person's features. Mathematical algorithms are then used to reduce that information to digital data. Some biometrics are more reliable than others. For example, the intricate patterns in the iris, the colored part of the eye, are considered better identifiers than even fingerprints.

The U.S. biometric system, known as the Biometrics Automated Toolset, or BAT, includes about 50 laptop computers equipped with scanners. The information on suspects is stored in a central database at a U.S. intelligence agency -- De Bolt declined to say which one -- in the Washington area.

An additional 400 laptops are being prepared for a possible Iraq invasion, said Anthony Iasso, a software engineer at Northrop Grumman Corp. who leads the project at Fort Huachuca.

So far, BAT data has been shared with both the FBI and the Immigration and Naturalization Service to help check the identities of incoming foreigners and of foreigners arrested inside the United States, officials said.

Tracking movements

De Bolt and Iasso said the BAT system aims to track the global movements of terrorists.

If a person catalogued and released in Afghanistan later turns up at a checkpoint in the Philippines -- perhaps using a different identity -- officials might begin investigating the suspect's background and links to others, De Bolt said. The suspect does not have to be apprehended, fingerprinted, or even identified by name.

U.S. authorities are supplementing the dossiers by adding surveillance photos and fingerprints gathered from, say, drinking glasses or magazine covers found in terrorist haunts. A suspect's dossier might also contain text from prisoner interrogations, video or sound clips and digital images of scanned items seized during a search, Iasso said.