Security professionals fear the limitations of metal-detecting security portals used to screen passengers at airports and visitors to public and private buildings. Metal detectors detect ferrous metal, but not gold, silver, copper, other non-ferrous metals, plastic, ceramics or composites — materials that can be used to make guns, knives, bombs and other weapons.

Detection technologies capable of overcoming the limitations of metal detectors have been around for years, but design and manufacturing limitations have prevented the development of appropriately sized, affordable products.

That may be about to change. During April's ISC-West show in Las Vegas, Brijot Imaging Systems Inc., Orlando, introduced a detection system capable of finding weapons, possible weapons and suspicious items concealed beneath a person's clothing.

With a combination of video and passive “millimeter wave” technology licensed from Lockheed Martin, the Brijot system scans individuals and crowds from close up to standoff distances up to 45 feet. Should the millimeter wave sensor inside the system detect a weapon or a material and shape that might be a concealed weapon, the system will alarm and send a video image of the person carrying the object to a security monitor. The image will include graphical brackets superimposed over the area of the person's clothing concealing the item. Inside the brackets, the system will print a description of what it detected: gun, knife or suspicious item.

“This product can bring a whole new mindset to weapons detection,” says Brian Andrew, president and CEO of Brijot. “You can use it to search for concealed weapons at access control points and standoff distances.”

The Brijot camera is not intrusive, Andrew says. While the passive millimeter wave sensor can detect and image many materials, it does not create recognizable images of people. In fact, passive millimeter wave sensors see people as gray shapeless masses.

The system also eliminates controversial pat -own searches. If it detects a concealed weapon or suspicious item, a security officer will simply ask the person to remove the object in, say, his left lapel pocket.

The passive millimeter wave sensor contained in the camera detects so-called blackbody radiation signatures, given off by everything in the universe — living, inorganic, naturally occurring or man-made. The system processes the signatures with sophisticated software algorithms and compares the results to its database of known guns, knives and assault rifles. Positive matches send a text message to the video output: gun, knife or bomb. Suspicious matches send a text message, and the graphical warning reaches the camera's video output in less than a second.

Developed by Lockheed Martin with a $200 million grant from the National Institute of Justice (NIJ), the technology detects millimeter wave radiation with by passive means. (An active system sends out millimeter wave radiation and analyzes more powerful reflected radiation. But a passive system only detects existing radiation; it does not send radiation out.)

At $60,000 per unit, the passive millimeter wave camera sounds expensive compared to conventional video cameras. But Andrew argues that this is a camera system, not just a camera. “The system has built-in intelligence,” he says. “It notifies security with an audible alarm sent to the security station or by e-mail. And three full-time officers are not needed to operate it, as with a metal detection portal.”

The marketplace appears to agree with Andrew's cost assessment. Prior to the official introduction of the product, Brijot announced an order backlog of $100 million in orders from distributors serving customers in the United States, Saudi Arabia, Singapore, Afghanistan, Egypt and 16 other countries.