Aviation Security Screeners, United States

Forensic investigations attempt to determine the cause of accidents and even to reconstruct (at least conceptually) the course of events leading up to and including the incident. In the case of an aircraft accident, where much of the evidence may be destroyed or damaged by a crash, the task is particularly challenging. Analysis of all data complied before and during the flight is useful in piecing together what occurred.

Analysis of the flight data recorder that is installed on many aircraft is a well-known forensic tool. However, air travel security technologies, which are in place principally to thwart aircraft high-jacking and terrorist opportunities, can also provide information useful to a forensic investigation.

One such technology involves the security screening that is a part of the pre-flight process. Aviation security screeners focus on both the passenger and luggage. Airline passengers are familiar with walking through a metal detector and having security personnel examiner them more closely using a hand-held metal detector. More recently, a walk-through machine has been introduced that can analyze the air flowing off of a person's body. The air can be rapidly analyzed, enabling the detection of non-metallic chemicals, which would otherwise escape the metal detector. The odor of the chemicals wafts off of the body along with the plume of heated air. Suspicious chemicals, such as those in plastic explosives, may be detected in this way.

Another routine part of air travel is the examination of carry-on and shipped baggage using an x-ray machine. The high energy x rays are able to penetrate through the suitcase to reveal the outline of the objects inside. A skilled operator is able to assess the contents based on their shape and translucency and focus on suspicious objects.

Chromatography is also routinely used to survey personal computers to verify that the computer case is not in fact housing an explosive. The object to be examined is swabbed using a fabric, which is then inserted into the chromatograph. The analysis takes only a few seconds to complete.

Documentation is another aspect of security screening. For example, passports provide an officially sanctioned photographic record and other information from a person. Concerns about the falsification of passports has led to the adoption of other documentation systems, including fingerprint and retinal scans.

Prior to the terrorist attacks of September 11, 2001, security screening at the more than 400 major commercial airports around the United States was the work of personnel employed by private firms that contracted with airlines. One outcome of the attacks was the Aviation and Transportation Security Act (ATSA), signed into law by President George W. Bush on November 19, 2001, which placed security screeners under the control of the newly created Transportation Security Administration (TSA). Early assessments of the new program were uneven, and TSA has encountered a number of challenges in what has proven to be one of the largest mobilizations of a civilian agency in U.S. history.

The fact that ATSA was written and passed just two months after the terrorist attacks serves to indicate the intensity of concern over air safety that prevailed in early fall of 2001. In fact, the bill would have passed even more quickly if it had not been for the thorny question of whether the government or private enterprise should control security screeners—and, assuming government control, whether Transportation or Justice was the department better suited for this task.

As of January 2002, TSA had just 13 employees, but by November 2002, a year after the passage of ATSA, there were 47,000 newly trained federal security screeners at airports nationwide. TSA spokesman Robert Johnson compared the mobilization to the rush of enlistees that followed U.S. entry into World War II in December 1941. Others were not as sanguine in their appraisal. Representative Harold Rogers (R-KY) maintained that the average screener at his home facility, Kentucky Bluegrass Airport in Lexington, processed just four people per hour.

All checked bags are supposed to be screened for bombs by TSA workers as of December 31, 2002. Screeners earlier began a practice of matching bags to passengers—that is, ensuring that for each name listed as the owner of the bag, there was a passenger with that name. Bag matching had been a practice on international flights since the 1980s, but many critics maintained that it would do nothing to stop suicide bombers such as those who perpetrated the September 11, 2001, attacks.

Much of the information used for aviation security screening is part of databases. Proof of citizenship is one well-known example. As well, the data collected in luggage and passenger pre-boarding security checks can be maintained for a set period of time. If the latter records are still available, a forensic inspector is able to trace the pre-boarding history of each passenger.