Video isn’t new, of course, but the quality and quantity of video available have increased dramatically in recent years.
“The fact that there’s so much video out there is creating both opportunities and burdens,” said Grant Fredericks, forensic video analyst with Forensic Video Solutions. He is a contract instructor at the FBI National Academy in Quantico, Va., and teaches at the Digital Media Evidence Processing Lab for the Law Enforcement and Emergency Services Video Association (LEVA). Rapid changes in technology have added to the challenge.
The experiences of the city of Vancouver, British Columbia, illustrate these rapid changes — and the challenges they present.
Back in 1994, hockey fans in Vancouver rioted when the local NHL team, the Canucks, lost in the Stanley Cup Final. Fredericks was in charge of the forensic video unit for the Vancouver police at the time, and his team was responsible for sorting through 100 hours of VHS tape to see if it offered any evidence that would help in the investigation.
Fast-forward to 2011, when the Canucks again played in the Stanley Cup Final, and again lost.
During the event, the police officers were focused on dispersing the crowd and preventing violence, not arresting individuals for damaging property, Montague said. But rioters also cost several million dollars in property damage, and police wanted to hold them accountable. So they put out a call for video of the event and received more than 5,000 hours of recordings from business security cameras, private cellphones and other sources.
“The sheer number of recordings from the riot was overwhelming, and many of the cameras used different formats,” Montague said.
Officials called in experts from LEVA, with whom Fredericks was working at the time. He and a team of more than 50 experts in Indianapolis viewed and analyzed all the video in about two weeks.
“Getting the data into a format that was viewable was at least half the job,” Fredericks said. The other half was watching all the video and tracking suspects from one video to the next.
The team set up a coding system to identify suspects by characteristics such as male/female, white/nonwhite and what type of clothing they were wearing. Since many of the fans were wearing Canucks jerseys and hats, they assigned a code to each type.
They then went through the list of people who had been tagged as committing criminal acts, entering the code for each person in the system to see if another analyst had seen the same person committing a different criminal act. That process was “almost automated, very quick,” said Fredericks. Although there were a few people who seemed to have committed just one crime, “in most cases these people were quite active.”
The police used social media, traditional media and a website to post the pictures of the offenders and ask for the public’s help in identifying them. Hundreds of suspects were eventually charged.
The story of the Vancouver hockey riots illustrates the challenges of video evidence — how to analyze thousands of hours of video from different sources — and the potential. And since 2011, advances in technology have increased both.
For example, Fredericks said that new products make it easier to play multiple types of video, something that would have made the investigation of the 2011 riots go more quickly. But as police officers adopt body-worn cameras, for example, and even more members of the public start recording events on their cellphones, the volume of video has increased.
Jonathan Lewin, deputy chief of technology and records for the Chicago Police Department, is working on solving these technical challenges for his agency. The goal is a scalable, cloud-based platform that will manage video evidence — whether from body-worn cameras, interview cameras in interrogation rooms or other sources — and deliver it to authorized recipients. It will also include still photos and digital audio from the 911 system.
“There’s a lot of content,” Lewin said. The department has been running a pilot project with about 30 body-worn cameras but is about to deploy them in much larger numbers. This, along with more content being digitized, means the volume of content will continue to grow.
Those working on improving the systems for gathering, storing and analyzing video evidence point to numerous ways it helps law enforcement and emergency management — advantages that could become even greater as the technology matures:
• Body-worn cameras protect both police officers and the community. “We expect police officers to handle some of the most challenging situations,” Haug said. “In this day and age of policing, everybody has a cellphone.”
Video evidence can help clear an officer who is accused of wrongdoing and can also help community members in cases where officers do overreach.
• Video evidence can help in court cases. Some cases that might otherwise have gone to trial are now being settled with a plea once the defense attorney sees the video evidence, said Haug.
In other situations, prosecutors may decide not to pursue a case after seeing the video.
• Footage can help with evaluation and training of police officers. Having video of difficult situations can help law enforcement leaders determine when the staff could use more training, and in some cases those videos could be part of the training.
• Video provides additional evidence in investigations.
“The most prolific sources of evidence available to law enforcement come from video images,” Fredericks said. And it’s not just the video of an actual event, such as a riot, that’s important. Once suspects have been identified and questioned, investigators can canvass the places they said they had gone in the days prior to the event and see if they show up on surveillance videos. This helps investigators test the suspects’ claims and in some cases learn more about people who were helping them.
“When we have that much video, we can tell a more complete and accurate story,” said Fredericks. “It makes a case that’s incredibly strong and often leads to guilty pleas.”
As the technology continues to improve, it could be even more helpful. For example, the Chicago Police Department has access to 26,000 cameras. “Can we make them more effective through technology? We don’t have 26,000 people watching them,” Lewin said. Instead, the department has people watching video in certain areas during certain hours, “but the sheer volume of video feeds makes it impossible to watch all of them.”
If analytics could help a limited number of human watchers know where to look on the surveillance videos, “it might be finding things that you don’t normally find,” he said.
Active monitoring of surveillance video is crucial to making it effective, said Nancy G. La Vigne, director of the Justice Policy Center at the Urban Institute. The group published a study in 2011 of how Baltimore, Chicago and Washington, D.C., were using surveillance cameras and whether they were effective. The study found two crucial elements to an effective program: saturating an area with cameras and having the video actively monitored by people.
“Active monitoring is pretty critical,” La Vigne said. But while agencies budget for the hardware and software required to run the systems, they don’t always think about what it will cost for people to watch them. This is an area where advances in technology may help in the future.
“If you don’t have the resources, then the only thing you can do is pull up camera footage after an incident” and hope it shows what you need, said La Vigne. Often, though, a critical event took place outside the camera’s view, for example, or the video quality wasn’t good enough to get license plate numbers.
Despite the potential of both current and future video evidence technology, there remain enormous challenges.
One is storage. “What do we do with the massive amounts of video files that we have?” Haug asked. “This is one of the biggest challenges that we’re facing in law enforcement right now. I work for a fairly small agency in north Idaho, with about 50 officers, and we have over 100 terabytes of video data from officers’ car cameras and body-worn cameras.”
Once agencies choose a storage solution — whether they pay a hosting service or do it themselves — other questions arise. For example, how long should video be kept?
Haug said there is good reason to keep it at least for a period of time. “You don’t know what you don’t know,” he said. Something that today is innocuous may turn out to be evidence tomorrow — for example, even video that doesn’t show a crime may show a suspect or his associate just beforehand or afterward.
Analyzing video is also a challenge. The Chicago Police Department recently received a grant to test analytics tools that can help flag video that a human should look at more closely, Lewin said. Some tools also help with redaction, or blurring faces of people whose identities should not be released.
“What can analytics do in an actual real-world setting?” asked Lewin. For example, will the software be able to flag unusual behavior — or alert officers to a traffic accident — even if the camera angle and lighting aren’t perfect?
Departments also need to be able to find specific video evidence when they need it. “If you have a whole bunch of video, it doesn’t do you any good until you have a way to catalog it, search it and store it,” Haug said.
Finally, making the video evidence accessible to those who should have access to it — and inaccessible to those who should not — is complicated. Exactly who should get access to a particular video, and when some parties’ faces should be blurred, is governed by law and departmental policy. The laws vary by state, though there are also federal privacy laws governing, for example, release of anything that might contain medical information.
The Seattle Police Department, for example, posts videos on YouTube after approving them for release. In other states, privacy rights may be stronger and the public’s right to see the videos not as strong. Illinois has a detailed law that took effect Jan. 1, 2016, covering not just how officers must use body-worn cameras but also under what circumstances the videos should be released to the public.
Technology may also be able to help with accessibility. Lewin said a good system can provide better controls and security than the old way of handing out copies of a DVD: Certain people have permission to view only, others can download and copy it, and still others can share it, for example.
“People can request a lot of things, and this will make it more efficient to comply with those requests,” said Lewin.
As they tackle the challenges posed by video evidence — and look forward to the advantages it can provide — experts expect the field to grow and mature.
“It’s an emerging technology. We want to see what the potential is,” Lewin said. “I think it’s a trend that’s going to continue.” k
