The rapid evolution of technology in recent years has put a lot of focus on what cutting-edge technology can do -- but can new ideas and tactics sometimes come from older technology?
For some police departments, the answer is yes. In the past few decades, they have found a specialized use for radio telemetry technology -- a method of transmitting a signal accurately through the air that was first developed in 1930 and subsequently used to track rockets.
These days, many municipalities allow for Alzheimer’s patients and people with autism to be equipped with lightweight transmitter bracelets that allow police to find them should they wander away from their caretakers. These same radio transmitters also help police track stolen items, such as bicycles, laptops, boats and firearms -- even drugs.
A small company based in southern Illinois is making much of this tracking possible. Called Wildlife Materials, which started out making transmitters for tracking animals, the company now has a division called Care Trak, which outfits police and sheriffs departments around the country with transmitter bracelets and tracking receivers.
“You see it in the news all the time,” said Mike Chylewski, vice president of Care Trak, “where they’re looking for some guy that has Alzheimer’s disease and wandered away from his house, and they get everybody in the world out there looking for him -- and dogs and helicopters and Boy Scouts and fire departments. This eliminates all that. And within minutes you’ll be able to tell what direction you’re in.”
Radio telemetry is extremely accurate, and with the right equipment, it’s literally possible to find a needle in a haystack. Police simply point the antenna in various directions until they get a signal on which direction their person went. “It’s like playing hot and cold when you were a kid,” Chylewski said.
Since police got their hands on this technology in 1986, he said, it has been used to find thousands of people, with an average search time of less than 30 minutes. But what's perhaps more interesting is how law enforcement has more recently started using the technology: They don’t talk about it often (and none would talk about it on the record), but radio transmitters are used in police and sheriff’s departments nationwide to curtail various illegal behaviors.
In one such covert operation, police found a field where a large crop of marijuana was being grown, Chylewski said, but they didn’t want to stake out the field for weeks or even months waiting for someone to harvest the crop. So the police department commissioned Wildlife Materials to make a radio transmitter small enough to fit inside a marijuana bud. An officer took the transmitter, which was painted green, and tied it inside a marijuana bud in the field.
Police could then track the harvest, but spend less time staking out the field. Once a day, or every couple of days, police drove within a half-mile of the field and could hear a chirp from their tracking receiver, indicating the plant had not yet been harvested.
Then one day, police turned on their receiver and it was silent, Chylewski said -- the field had been harvested. “Now what they do is either drive around town and see if they pick up a signal somewhere, or they go up in a helicopter,” he said. “And that’ll give you 10 times the tracking range.”
Eventually, Chylewski said, police picked the signal back up in town and tracked it to a man’s basement. Police found $250,000 worth of drugs in that basement, and the grower was given a three-year prison sentence. “This guy had been growing dope for about 10 years,” he said. “The cops were just tired of playing his game, so we focused on it and took care of it.”
The applications of radio telemetry for law enforcement are almost limitless. “Years ago, we used to put transmitters in executives' brief cases that were going down to South America because of the risk of kidnapping,” he said.
But what is more common today is using radio transmitters to bait and track high-theft items. Chylewski has worked with police around the country to identify theft of everything from bicycles, laptops and boat motors, to piles of 2x4’s on a construction site.
Typically police will bait thieves with a commonly stolen item, he said, and hope that they find someone who was a big contributor to local theft. “We’ve recovered thousands of bicycles from universities by baiting the bicycle,” he said, adding that in some cases police use GPS also, but sometimes it doesn’t work because of GPS’ limitations.
For tracking some things, like cargo or vehicles, GPS can be superior, but when tracking people or trying to find which apartment unit a potential thief is in, telemetry is more accurate, Chylewski said.
GPS also requires a lot more power than telemetry. In the case of the marijuana bud, a GPS transmitter probably would have lost battery power before the field was harvested. The radio transmitter was on for 21 straight days, Chylewski said. “Sometimes high-tech is great,” he said. “But there’s other times where low-tech works much, much better.”
Colin wrote for Government Technology from 2010 through most of 2016.