Law Enforcement Technology
LifeGuard tracks criminals where they hide

A Flock of Seagulls” once crooned,“You’re trying to hide away from me,away from me. Don’t you know that you can run but you can’t hide away?”

Criminals will soon find truth in those lyrics if they try to conceal themselves from the long arm of the law. DKL International now offers a solution to help law enforcers find bad guys wherever they hide.

The Vienna, Virginia, company, offers LifeGuard, a handheld ultra-low frequency electric field detector designed to spot a human electric field. With this device in hand, officers can scan buildings, vehicles or other areas where direct observation of the presence of human beings is prevented or dangerous.

To date, LifeGuard is prominently used in Asia, where public safety officials deploy it to track signs of life after earthquakes and mining disasters, detect people in burning structures, scan shipping containers, and hunt for illegal immigrants on coastal freighters or fishing boats. DKL also positioned LifeGuard teams at the World Trade Center for the first 10 days after 9/11, and these searchers were able to find numerous missing rescue workers.

“Law enforcement folks really need to see this unit,” says Chief Stan Tarnowski, suppression section chief at Georgia Fire Academy, a division of the Georgia Public Safety Training Center. “With all the hurricanes, natural disasters and other things we face every day, this equipment should be placed on every rescue truck and patrol vehicle in every fire and police department.”

LifeGuard basics

The DKL LifeGuard, Model 1, is a handheld instrument, weighing about 2 pounds. The black plastic case has a pistol grip handle and can be configured for both long- and shortrange operations. The range adjustment device (RAD) on the LifeGuard’s snout, resembles an antenna, but instead of receiving an electromagnetic signal as a radio or TV antenna does, it detects the edge of an electric field.

To operate, a user simply holds the grip in his hands and aims the RAD in the direction he wishes to scan. The RAD should point slightly outside the area to be searched, notes John Montanio, retired chief of the Culver City (California) Police Department, the first LifeGuard tracks criminals where they hide A “ LifeGuard user in the United States. The former deputy director of the anti-drug task force, LA IMPACT, notes if the section to be searched lies directly in front of the user at 0 degrees, he should swing the device clockwise past the area approximately 10 degrees then move it back again.

Whether a person lies in that locale becomes clear after doing this a few times, he says, explaining the device travels very freely when nothing is detected, but stops moving freely when something is.

“When you get a detection, you know you’ve gotten a detection,” he says. “I don’t know how to explain it, except that the device kind of drags.”

Once the system locks onto a subject, it’s possible to track him as he runs. “The snout of the unit moves as the person moves,” Tarnowski says. “If they move to the left or the right, the LifeGuard moves with the person.”

The first-generation LifeGuard, Model 1, can locate and track any living being up to 500 yards away in open areas, and find individuals at shorter distances when barriers such as concrete walls, steel bulkheads, heavy foliage, earthquakes and up to 10 feet of water stand in the way. It can detect and lock onto a person in 3 to 5 seconds as well as distinguish a human from other animals.

Model 1 presently does not offer digital readouts of search results unless it is connected to a computer. “It’s all feel,” says Montanio. Departments may purchase this device with or without the ability to connect to a computer. While the unit operates similarly either way, the user receives visual and audio signals in addition to drag when the device is connected to a computer.

DKL president and founder Howard Sidman advises departments purchase the unit with computer hook-up capabilities for training. “Most operators don’t take the computer into the field once they’ve used the product for awhile,” he explains. “They feel confident enough to use the equipment without the computer.”

The system operates on rechargeable batteries that take up to 6 hours to recharge but provide 12 hours of operation — if the user operates the system the way DKL advises. Running the system’s optional laser significantly shortens battery life, Sidman explains. “The laser is nice because it shows everyone in the search team what direction the detection is in,” he says.

Model 25, currently in the prototype phase, is smaller in size than Model 1. This second-generation product will be able to detect people through 1-meter-thick concrete walls within a range of 20 to 50 meters. Designed for the rugged public safety environment, this prototype will also feature reduced battery weight and size, as well as present digital readouts of detection data.

Detecting life

The unit locates and points toward an irregular electric field generated by the human body. Electricity produced by the heart, which makes up 97 percent of this electric field, creates electrical impulses at ultra-low frequencies (less than 30 cycles per second), which travel through barriers that absorb or reflect higher frequency energy.

While the system could be used to detect a variety of electrical frequencies, its designers matched the instrument to a human being’s electric field, Sidman says. Because the heart produces the majority of a person’s electrical field, the system can find individuals — even when they are immobilized — as long as their heart is beating.

Human beings are not the only living creatures with four-valve hearts, however. If cows, monkeys and other animals also have fourvalve hearts, how is it possible to distinguish between them?

DKL equips the device with an SPF filter to differentiate between humans and that of other living creatures or inanimate objects. “We looked at different field presentations and found the human electric field to be unique,” Sidman explains. “We then developed a filtering circuit that allows us to match to that specific field.” This circuitry ensures the system only reacts in the presence of a human electric field. He describes it as tuning in to a specific station, much like a person does with a radio.

Pinpoint accuracy

But how accurate is it?

That’s a burning question on everyone’s minds, admits Sidman, especially since a 1998 test of the product by Sandia National Laboratories reported the system had just six successes in 25 trials.

Sidman explains the negative reports pertain to a prototype that never went into production and no longer exists. He states, “Since we’ve brought the Model 1 out, 3 1/2 years after the report, we’ve continued to improve the product, having made five or six hardware changes and improved the< software an equal number of times.”

He attributes the negative reports to a discrepancy in the definition of a successful detection. Sandia researchers labeled a successful detection as when the device pinpointed a person’s location with 100-percent accuracy. “If we were off by a couple of degrees at maximum range, we didn’t get any credit,” Sidman explains.

But that’s not how the device works. The LifeGuard points users in a subject’s general direction then becomes more accurate as the operator closes in on the target.

Success also varies by the number of barriers between the device and a subject. “If you are in the open air, it points right at the subject,” Sidman explains. But if an officer is 300 to 400 meters away from a person, and there is a lot of barrier (trees, concrete walls, etc.) between them, the device will only point the user in a direction in which to move. The system may be 5 to 6 degrees variant from where the person actually is but as the officer moves closer, and the amount of barrier is reduced, accuracy improves.

“For a search in the woods, we can get within visual distance of where that person is,” Sidman says. Once officers close in, they should employ faster procedures, such as search dogs, night vision, or foot pursuits, he adds.

The device can quickly search large spaces to reduce the target search area, which may have a 180-degree arch at the pursuit’s onset. “The value is that we can explore that 180-degree arch out to 400 to 500 meters, and if there’s someone within that detection range, we can provide a narrower bearing,” says Sidman. “Then rather than search the entire 180-degree arch, officers can head out in a 4- to 5-degree area.”

Montanio recalls his first field application of the system. He received a call on Easter night from the Los Angeles Sheriff’s Department requesting assistance at a scene where a suspect had taken hostages and barricaded himself inside a City of Industry residence. Officials wanted Montanio to use the LifeGuard system to determine where people were located within the home, in case they had to do a rescue entry.

He recalls deploying the system on all sides of the home and getting two detections, one in the dwelling’s center and the other in its northeast corner. When the suspect surrendered and SWAT officers entered, they found the subject and hostages holed up in the center of the home while a baby slept in a bedroom in the northeast corner.

In another incident, as undercover officers made a methamphetamine buy in south Los Angeles, the suspect took off running into a large warehouse. Montanio says he was able to use the LifeGuard to narrow the suspect’s location to a small corner of the warehouse. K-9 officers located the suspect hidden in a locker near where Montanio had made the detection.

Tarnowski says a double blind test in the woods near the academy produced a 96-percent accuracy rate. “We have found that every time the unit has been used, we were able to detect where the individual was, be it under ground, above ground, through a building, through steel, through electrical transformers and from the air,” he says.

Its strength is its consistency, he adds. “It’s not one of those things that works one time, and then five times it doesn’t.”

This spells bad news for crooks hoping to outrun the long arm of the law. When officers are armed with a LifeGuard, suspects can run but they can no longer hide.

Courtesy of Law Enforcement Technology magazine.

For more information go to


Chinese Law Enforcement
DKL International, Inc | 501 Church Street, Suite 317, Vienna, VA 22180 | 703.938.6700 | Fax: 703.562.1953 |