Gathering video evidence wirelessly

     The number of video cameras in police vehicles across the United States is approaching 20,000, according to a recent report by the International Association of Chiefs of Police (IACP), which found these cameras enhance officer safety, improve agency accountability and reduce agency liability.

     But once upon a time, the idea of putting video cameras in police cars was frowned upon and criticized by law enforcement officials. And, civil rights activists and social libertarians once called these systems "big brother" personified.

So what changed?

     According to video surveillance proponents, the tragic events of September 11, 2001, changed everything. "The Constitution's protections are unchanging, but the nature of public peril can change with dramatic speed, as recent events show," wrote U.S. District Judge Charles Haight in a critical ruling that reduced restrictions on police surveillance of political groups in New York City after 9/11.

     After this court decision, many law enforcement agencies began embracing the technology. "It's not really a Big Brother state," says police Capt. Bill Fisher, commander of the civil affairs unit in the Philadelphia (Pennsylvania) Police Department, of Pennsylvania's use of video surveillance systems. He says Pennsylvania agencies partly use videotape to gather proof that officers are not breaking the law in cases where police brutality is alleged. Seattle's Mayor Greg Nickels adds using digital cameras in this way helps build trust (in law enforcement) by providing what he calls "objective evidence" of police encounters with residents.

     Their words ring true throughout the country as more and more law enforcement agencies adopt modern surveillance methods and equipment, and reap similar benefits.

     In Pennsylvania's Buskkill Township the use of mobile video systems helped reduce the amount of time officers spent in court on DUI and other cases involving traffic violations. As a result, Buskkill Township is pursuing additional grants to equip more police vehicles with cameras.

     Los Angeles Police Chief William Bratton is also a strong proponent of in-car surveillance systems, and wants digital cameras installed in all of the city's 1,600 patrol cars. It is estimated the California department could save $3 million a year in costs to investigate complaints against police officers.

Wireless trends

     But another reason for the growing acceptance of video surveillance is the advent of new wireless technology and less bulky equipment. Video can now be recorded digitally and transferred quickly using wireless network technology.

     The old ways of transferring files were just too cumbersome and flawed, adds Craig Cigard, product manager for Lenexa, Kansas-based Kustom Signals. "We knew agencies would be interested in wireless technology. They could see the advantages."

     Technological advances also allow recorded evidence to be stored compactly and more efficiently on compact discs (CDs), universal storage drives, digital storage devices and other data repositories. The days of archiving videocassettes that occupy shelf or cabinet real estate are coming to an end.

     Using wireless systems further protects the integrity of video evidence, Cigard adds. "A lot of agencies don't want officers touching evidence. When someone is pulled over for a DUI, for example, the video from the car system is evidence that either exonerates an officer from a liability claim or puts someone in jail. From both evidentiary and productivity standpoints, agencies want to substantially reduce or eliminate officer interaction with the video."

Wireless video systems

     A typical IP wireless video surveillance system contains the following primary components: digital cameras, mesh network nodes or access points (APs), gateway nodes, backhaul units, servers, monitoring stations with surveillance software and someone to monitor the cameras.

     And, technically speaking, typical wireless data communication manages keystrokes, e-mail messages or reasonably sized files maxing out at 5 to 10 MB. But continuous streaming video recording in a digital evidence-gathering operation is unique and requires an average 100 MB or more storage capacity for each camera in use. Each patrol car takes at least 1 hour of MPEG1, MPEG2 or MPEG4 video per shift, and that file takes about 5 minutes to transfer from car to server. As more cars pull up to the police station or law enforcement facility, the amount of time required for downloading doubles with every new car.

     Kustom Signals' wireless solution speeds the transfer process by relying on three to five APs from D-Link, a Fountain Valley, California manufacturer of computer networking equipment. The APs are mounted on each exterior wall of the police station and a similar access point is installed in each squad car equipped with an 80-GB disk drive for video storage. The D-Link APs, chosen for their rugged durability and resistance to heat, cold, dust, dirt and humidity, host an embedded Microsoft Windows XP-based program that initiates an FTP (file transfer protocol) session when the vehicle approaches headquarters.

     According to Cigard, the officer drives his patrol vehicle up to the police station and into the wireless zone, then goes inside the building. By the time the officer returns to his vehicle, the file download is complete and the in-car disk drive is ready to store more video.

     "The officer doesn't have to take anything out of the car. There's no removable hard drive or tape, and there's no need to run an Ethernet cable. Nobody has to do anything," Cigard says. "Productivity increases and the law enforcement agencies are able to gather unquestionable, untainted evidence automatically."

     Video files transfer to back office servers into a database housed in 10-, 12- or 18-terabyte (TB) storage disks equipped with RAID for file backup, or in NAS storage enclosures. Officers can easily locate videos on this system to view, and burn DVDs to take evidence to court.

Pros and cons

     As with any new technology, there are both pros and cons to wireless video surveillance transfer solutions. The advantages include:

  • Lower costs - One of the biggest advantages of wireless surveillance technology for law enforcement applications is the lower cost. Almost 80 percent of the expense of installing a wired system is associated with cabling and trenching. In many cases, city, state and federal grants are available to offset costs.
  • Ease of installation - Eliminating the use of wiring will typically cut the installation time down to weeks instead of months for a traditional wired network.
  • Portability - Today's network equipment, such as D-Link's APs, are light enough to carry.
  • Self-healing - A wireless network will continue to operate even if one AP fails.
  • Versatility - Wireless networks dramatically expand mobility and flexibility, with easy access to voice, video and data streams.

     Possible disadvantages include:

  • Lack of knowledge - Most law enforcement agencies need to rely on reliable wireless solution integrators to install their systems. However, with proper training, a wireless video network is very easy to operate and maintain.
  • Insecure data - Despite widespread opinions to the contrary, today's technologically advanced wireless networks provide more than enough security for any application.

     No matter how you slice it, the benefits far outweigh any potential disadvantages, and as a result many agencies are turning to wireless networking because it saves both money and time.

     "The wireless camera system dramatically improves our ability to monitor certain areas of the city," says Tom Lawrence, deputy chief of the Dallas (Texas) Police Department.

      "We can now provide our officers with critical, real-time information they can use to protect the public and themselves whenever an incident is detected."

     And that has a value money cannot buy.

     Les Goldberg is a freelance writer and former newspaper reporter based in Orange County, California. He has been writing about technology for the past 35 years.