Law-enforcement technologyEncrypted police broadcasts sparks battle

With advances in technology it is now possible for ordinary citizens to cheaply and easily listen in on police broadcasts, which is why law enforcement agencies across the country are working to shield their communications systems.

Departments across the country have increasingly moved to encrypt their broadcasts in an attempt to prevent criminals from evading arrest by listening to officers communicate.

Testifying before a Washington D.C. city council committee, Cathy Lanier, the head of Washington, D.C.’s police force, said, “Whereas listeners used to be tied to stationary scanners, new technology has allowed people — and especially criminals — to listen to police communications on a smartphone from anywhere.”

“When a potential criminal can evade capture and learn, ‘There’s an app for that,’ it’s time to change our practices,” she added.

According to Lanier, D.C. recently began encrypting its communications after it was discovered that carjackers operating around Capitol Hill were using their smartphones to listen in on police broadcasts to evade capture. It was only after police stopped using their radios were they able to catch the criminals.

Journalists and scanner hobbyists have opposed the encryption of police broadcasts arguing that newsgathering is impeded and open communications help ensure that neighborhoods can spread safety information as quickly as possible.

Critics of the trend say if police need to share information secretly, they have ways of doing it already and do not need to encrypt routine broadcasts.

“If the police need to share sensitive information among themselves, they know how to do it,” said Phil Metlin, the news director of WTTG-TV, in Washington. “Special encrypted channels have been around for a long time; so have cellphones.”

Meanwhile, David Schoenberger, a scanner hobbyist who lives in Fredericksburg, Virginia, said encrypted broadcasts could be useful in some instances, but not all.

“I think they do need to encrypt the sensitive talk groups, like the vice and narcotics, but I disagree strongly with encrypting the routine dispatch and patrol talk groups. I don’t think that’s right,” he said. “I think the public has a right to monitor them and find out what’s going on around them. They pay the salaries and everything.”

Scanner hobbyists and journalists are no longer the only ones able to listen in on police broadcasts. Several companies have designed apps that allow smartphone users to easily listen in broadcasts.

One app, called Scanner 911, advertises on its website that users can “listen in while police, fire and EMS crews work day & night.” Apple’s app store sells several similar products as well.

Encrypted police radio systems are increasingly more common as departments upgrade their equipment from analog to digital, but logistical challenges and costs still make secret broadcasts a rarity.

With digital radio equipment, voice signals are sent as data streams that are then converted into high-quality audio.

Encrypted communications devices only allow listeners with the right key to listen in, while others only hear silence or garbled talk. In large cities, encryption is rare as it is difficult to keep track of encryption keys with a large force and if too many people have access the system becomes useless.

The cost to install encoded police systems varies, but the Nassau County police department in New York is in the final stages of installing a $50 million emergency communications system with encryption capabilities.

The battle over encrypted police communication may be a moot point.

According to Matthew Blaze, a researcher on security and privacy in computing and communications systems at the University of Pennsylvania, few local police departments have encoded broadcasts and most cities with modern radio systems are difficult to monitor without sophisticated and expensive equipment.