Even so, in a country with no fingerprint files or vehicle records, authorities still do not know who was behind the attack.

Hoover made changes, such as expanding and combining fingerprint files in the Identification Division to compile the largest collection of fingerprints ever.

By the time he stepped down in 1973, Dr. Gallati had a computerized fingerprint file of some 3.5 million individuals.

An FBI computer specialist said later that the wide-base search of the fingerprint files would have identified them in "another four to six hours, max."

At the time, he included the Bertillon system alongside the fingerprint files.

Depending on the live-scan equipment used, a single fingerprint file can amount to 1.5 million to 2.5 million bits of information.

"The problem is that we don't always have a complete fingerprint file to match them against, so we may not be able to identify the criminal."

There's no record of them in the FBI's fingerprint files.

It used to be in the old days we would write what I call the little fingerprint file on the root of the drive.

The fingerprint files were not in quite the same condition that Steve had described.