Fifty Years of Police Technology

Article excerpt

What passed for technology in, 1953 is an antique today, although the basic mission of crime suppression and investigation has not changed. A world of new technology exists. Take a close look at the development of forensics, breath testers, in-car video, and digital cameras: the technologies that appear to have seen the greatest advances and obtained the most widespread acceptance.


Detectives have long been dependent on the boys in the lab to refine raw evidence and link physical evidence to suspects and victims, and many cases have been broken through some miracle conjured up by a criminalist. The problem that criminalists often had in the analysis of evidence was one of an embarrassment of riches. A clear, complete latent print left at a crime scene was close to useless when there was no suspect to compare it to. While it was technically possible for a fingerprint examiner to compare a latent print with all of those already on file, the millions of tenprint cards stored by the FBI, state criminal records repositories and local agencies often made this task impractical.

The widespread availability and lower cost of computers automated this process. A computer can scan a print pattern and reduce it to what amounts to a very long number, based on the presence or absence of information in the area analyzed. This number can then be compared to print records that have been similarly scanned and classified, and at a rate several orders of magnitude faster than a roomful of print examiners could accomplish. The process of comparing a latent print to each of 10 inked prints on millions of tenprint record cards would be enough to drive the most patient person insane, but computers do not bore easily.

This system, which came to be known genetically as the Automated Fingerprint Identification System (AFIS), can compare a latent print to as large a sample as desired (although system-wide comparisons still take considerable time), and at the same time consider every orientation of the print, since it isn't always evident whether the examiner is looking at a latent print right side up, upside down or sideways.

There is still a potential for missing the match between a latent print and someone who has a record card on file, because there are millions of tenprint cards that have never been entered into the system. This is a time-consuming task, and one that takes up computing power and storage space, which is always at a premium. Tenprint cards of military inductees that have never been charged with crimes, civil service employees, and applicants for licenses as teachers and physicians are often excluded from the scanned sample, because of the relatively low incidence of criminal behavior among these groups. Even record cards obtained from arrestees are often excluded, depending on the nature of the charge, because there is always a backlog of cards obtained from dangerous felons waiting to be entered into the system.

A process that may eventually get nearly everyone into the AFIS network involves the use of live scan equipment. Live scan employs electronic scanners that record fingerprints instantly and without any ink or chemicals. Wireless technology is even bringing live scan to the street. Handheld and car-mounted scanners can record and transmit a single print for comparison, immediately confirming identity and wanted status if the person is in the system.

Many states are encoding rudimentary print data on their drivers' licenses, so that license holders can confirm their identity and the authenticity of the license to officers in the field immediately. The limiting factor on the proliferation of this technology is money. Until the hardware becomes cheap enough for every law enforcement agency to afford it, many officers are going to be using the old-fashioned methods.


Blood left behind at a crime scene in the 1950s was considered good evidence, but not great evidence. …