Image is Everything in Stopping Crime
The potential for CCTV systems to help banks and other businesses catch criminals red-handed often goes unrealized, replaced by a reality in which the image is so blurry that neither red hands nor identifiable faces can be made out. Frustrated by the problem, public and private security professionals are developing guidelines for obtaining evidence from video recorders and for ensuring that the images can be placed on removable media for law enforcement.
The problem frequently stems from how systems are configured by end users. As a result of those setups, police forensic experts are asked to work wonders with footage that has been overly compressed or otherwise lacks critical detail. “Quite frankly, the quality of images we’ve been getting from these systems is horrendous,” says Richard Vorder Bruegge, a forensic video specialist with the FBI.
The image-quality problem has particularly affected banks, causing Dan Badony, the FBI’s bank robbery coordinator in Los Angeles, to work with local security professionals in the last couple of years to develop some guidelines. At the request of FBI headquarters, that process has been moved under the aegis of the Scientific Working Group on Imaging Technologies (SWGIT), an FBI-sponsored body comprising members from all levels of law enforcement. It has expanded into a broader effort to craft guidelines to help all businesses maximize CCTV image quality. The project’s progress was recently discussed at an ADT-sponsored symposium on financial services security concerns.
Among issues likely to appear in the draft guidelines, compression has caused the most concern for CCTV system owners, says Vorder Bruegge. The guidelines are expected to call for less compression than is standard practice today, because compression—the process of reducing storage requirements by removing frames from footage—often strips vital detail from images, making it the bane of forensic analysts looking for subtleties such as clothing patterns.
System owners counter that compression is critical because it reduces storage costs. Those concerns are recognized by law enforcement, says Vorder Bruegge, and it is likely that the draft “will say to use the lowest possible compression for critical images,” Vorder Bruegge says.
Other issues are less controversial but also important, including camera placement. For example, the guidelines will likely recommend that a single camera be dedicated to each teller and customer-service station. System operators will also be urged to adjust their cameras to achieve a field of view in which a person’s head and shoulders take up 15 to 20 percent of the frame, Vorder Bruegge says.
In addition, the guidelines will direct system users to make images available to law enforcement in a removable medium. “Banks don’t like their systems ripped from their walls,” Vorder Bruegge says.
Another goal of the guidelines is to encourage the use of a nonproprietary format for digital files so that law enforcement can access the images instantly. Part of the problem in the past has been the inability of local police to open an image file and view it. Since police can’t afford to invest in a multitude of proprietary CCTV systems, the only solution would be standardization.
The guidelines may also help make digital images stand up as evidence in court. The issue is relevant for recorded images that haven’t been monitored (if they have been monitored, then a witness can swear that the footage is accurate). In those cases, courts require that systems be shown to operate correctly. Once again, compression plays a role. Highly compressed video streams, “can generate artifacts (defects) in images that make it appear that a person was in two places at once,” says Vorder Bruegge.
Even without these guidelines, CCTV users can simply and quickly improve image quality, says FBI Forensics Examiner Thomas Musheno, who attended the ADT symposium. He suggests reviewing CCTV images to see whether regular customers and staff can be recognized. If not, adjustments are definitely in order.
Some observers fear that courts and insurers will interpret the guidelines, especially given its association with the FBI, as a de facto standard. The concern is that commercial establishments that don’t follow the guidelines to the letter will incur liability. “We’re well aware of this,” Vorder Bruegge says, but he notes that the document states its explicit purpose as a guideline up front. And if courts and insurers adopt them as standards anyway? “We can’t get bogged down in politics,” he says. “We have to do what’s good for law enforcement.”