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Scoping Out Malicious Mail

WHEN A HEAVY, unmarked box arrived at the mailroom of the 704th Military Intelligence Brigade at the Intelligence Security Command (INSCOM), wary postal personnel immediately scanned it with their high-powered MailScope x-ray machine. The suspicions of the team—stationed at the National Security Agency at Fort Meade, Maryland—were borne out: detailed imagery on the computer screen showed a cache of about 20 grenades.

Although the grenades were later found to be legitimate training weapons ordered by the brigade’s supply office, the incident underscored the effectiveness and raison d’etre behind the MailScope: to protect VIPs from harm that could surreptitiously come via the postal service.

In the case of the INSCOM, the mailroom handles about 10 packages per week for various military intelligence commanders and about 50 individual soldiers. “There is a high amount of classified information that comes through here. That’s why we assume we are a target,” says mailroom head Specialist Michelle Hiles.

New Jersey-based Glenbrook Technologies Inc. has been refining the MailScope for 22 years. An extremely high-intensity x-ray machine, it can detect within a package a single match head or three grains of table salt sprinkled into an envelope. If 100 letters are lined up at a 45-degree angle and examined by the machine, it can spy a credit card within one of the envelopes and clearly read its number.

Glenbrook president Gil Zweig says that his firm has achieved such microscopic precision by reversing the x-ray process. Whereas common x-ray screening technology takes a large object and displays it as a smaller image on a video monitor with reduced resolution, the MailScope scrutinizes a tiny 50-millimeter field of view, then magnifies it on a video monitor up to 40 times.

Zweig says that the process allows for 20 times the amount of detail to be displayed. The screen images can, therefore, divulge small quantities of particles, powders, plastic explosives, fluids, biohazard desiccants, and microcircuitry. This type of precision is especially important for mail screening, versus screening of personnel at an access control point, because threat items in mail will often be small.

“Mail threats are often very subtle ones—a hypodermic needle filled with HIV-positive blood, or a match-head booby trap [incendiary device],” says Zweig.

Less subtle threats, such as homemade bombs, also may be among the threats that come through the mail, he says, but they are easier to detect with standard xray technology and not, therefore, the threat that would cause a user to want the

MailScope x-ray. Even a letter bomb needs a hefty power supply, such as a battery fit for a cell phone or a computer, Zweig reasons. Any x-ray system would have picked up “Unabomber” Ted Kaczynski’s deadly handmade explosives, for example. MailScope’s detailed images need to be studied by an operator who knows what to look for. Zweig says his company can train an operator on how to spot rogue elements in x-ray images within a half hour, educating the user via a library of images that show credit cards doctored with wire, match heads, particles, and other displays.

Instructions accompanying the machine stipulate what items are appropriate in a letter going to a “high value” person: paper clips, staples, credit cards, or memory media such as floppies and CDs. Anything else that cannot be clearly identified prompts investigation.

Specialist Hiles says that training to use the machine takes a mere 20 minutes and covers the basics: how to turn it on, how to activate the x-ray mechanism, and how to operate it. What takes somewhat longer is building experience and education necessary to properly interpret MailScope’s images.

“The operator has to have a priori knowledge,” says Zweig. Eyebrows should rise at the sight of anything that looks like a particulate, or a grain, or has a mottled appearance possibly indicative of an explosive. Operators need to be schooled in spotting items such as match heads or powders.

“If you know what something looks like, you are going to know what it is [on MailScope],” says Specialist Hiles. For bomb expertise, Glenbrook taps Securesearch Inc., of Scarborough, Ontario, a training firm specializing in security.

The MailScope comes as a desktop or a console on a trolley with wheels. The latter is the most common client purchase. A large box with a computer screen next to it, the MailScope is accessed by opening a hinged door. A parcel or letter tray is inserted, and the user clicks on a little bar at the bottom of the computer screen to activate the x-ray.

The operator sees a real-time fluoroscopic image on the monitor, and continues to scan the parcel millimeter by millimeter using a joystick. An 8-inch package would require four passes, examining two inches (50 millimeters) at a time, but the process takes no more than a minute. An operator can take whatever time is needed, however, and zoom in on any item that looks troublesome.

Readying the MailScope for use is a matter of inserting a key, flipping a few switches, and waiting for the program to boot up on the computer monitor. There is no warm-up time required, and the machine can be left running 24 hours a day.

The MailScope cannot detect anthrax, but it can see very small quantities of silica, which is often mixed with anthrax to keep it dry so that it can become airborne. The machine can also pick up the presence of Semtex, a general-purpose plastic explosive popular with terrorists.

In general, anything that appears light in color within the MailScope image is organic. Semtex, for example, would appear light grey, and it would have a mottled appearance because of its putty-like nature. If it showed up on the screen with a cylinder embedded in it, it would be highly suspect as a detonator of some sort.

MailScope costs $52,000, including installation and training. Other users include the Law Enforcement Academy of Singapore, various military installations, and a pharmaceutical company.

(For more information: Glenbrook Technologies Inc; phone: 973/361-8866; e-mail:[email protected])

Robert Elliott is an assistant editor with Security Management.