Terrorist-Fighting Sleuths Get Help from "Taggants"
By Christopher B. Cohen
(as appeared in the 5/13/95
Sixteen years ago, on May 10, 1979, Nathan Allen left work at
Bethlehem Steel Company's
As he turned on the ignition, the truck exploded in the parking lot. Allen was killed and his passenger injured. The murderer soon was arrested and convicted due to a new invention for "tagging" explosives.
After the explosion, agents from the U.S. Bureau of Alcohol, Tobacco and Firearms examined the site for evidence. They found microscopic, plastic, color-coded chips called ''taggants"-part of an ATF pilot program in 1978 and 1979. The color code lists given to the ATF allowed it to trace the explosive used in the bomb.
In the 16 years since, thousands of bombs have shattered lives of
otherwise ordinary Americans with little notoriety. Then came
the bombings at the
Since Allen's killer's 1980 conviction in federal court in
To aid law enforcement, the colored striped codes in the plastic flakes are changed after each shift at the explosives plant. During manufacturing, they are given magnetic and fluorescent qualities. This means detectives and investigators can more easily find these tiny specks by shining ultraviolet light on debris left at a bombing site.
Investigators can place a magnet inside a small plastic evidence bag turned inside out. When the magnetized particles are drawn to the plastic bag, it is turned outside in with the evidence sealed inside. Bringing a microscope to a truck's tailgate allows investigators to read the code right at the bombing site. They compare it to the code book and immediately contact the manufacturer and retail outlet.
In 16 years, bills have been introduced in Congress to help trace the
source of bombings. None passed. Insertion of tagging devices into all
manufactured explosives and potassium nitrate is opposed by the
Taggants are the size of pepper flakes. Those who argue against their use say that they would add to the cost of explosives and thus damage the mining and oil exploration businesses that use these commercial products. Others want an exception so taggants will not be placed in gunpowder-a favorite substance for making pipe bombs.
Still others don't want the plastic specks put into fertilizer, which can be combined with fuel oil to produce powerful bombs.
Democratic anti-terrorism legislation has yet to be released but it is likely to require the treasury secretary to study tagging explosives, making fertilizer inert and controls on bomb components.
If you have questions about this article please contact Christopher Cohen at 847/867-8500 or 847/835-4002.