CCTV plays Sherlock

The article by Raj Shekhar, Arun Dev, V Narayan & A Selvaraj with inputs from Sindhu Kannan and Somreet Bhattacharya was published by the Times of India on April 24, 2016. Pranesh Prakash was quoted.

In case after high-profile case, cameras have been the big stars of Delhi police investigations in recent months. After the Civil Lines hit-and-run case, where a 17-year-old driving a Mercedes was caught on camera speeding away from his victim, reliable witness to the crime came from a nearby CCTV. A few weeks ago, in the Vikaspuri lynching on Holi eve that threatened to take on communal colours, it was CCTV footage that clinched the case.

Across India, police officials reel off cases where CCTVs have made all the difference in identifying offenders and speeding up investigations. "Petty crimes like snatchings have been brought down by 50% in areas like Chandni Chowk since 2014," estimates Madhur Verma, DCP (north), Delhi Police. "Even if the face cannot be fully recognised, the timing shown on the CCTV grabs, and proof of the accused being present at the spot, can be useful corroborating evidence for the court," says DCP Dhananjay Kulkarni, explaining how CCTV helped nail the infamous "chaddi baniyan gang" in Borivli, Mumbai.

CCTV cameras have proliferated across our public spaces in the last few years, mutely observing our movements. It's not just the police; shops, companies and individuals install them too, and these come in handy for law enforcement. For instance, Delhi has about 1,79,000 CCTV cameras installed around the city, out of which 4,000 have been placed by the Delhi government, and the rest by private agencies who collaborate with the Delhi Police under its 'Eyes and Ears' scheme. "Cameras are a fact of life around the world, there's no going back for the police or for anyone else," says N Ramachandran, a former IPS officer, now president of the Indian Police Academy think-tank.

Whether London, Boston or Bengaluru, it is often a terrorist attack that shocks a city into ramping up its CCTV network. After the Church Street attacks, the police got cracking on surveillance, using crime-mapping techniques and shortlisting vantage points. While they currently use 300 cameras, the police believe the figure must be taken up to 2,500 to keep a better eye on the city.

But does CCTV control crime? To that question, there is only one unsatisfying answer — it depends. The debate is torn between those who see CCTVs as the embodiment of an eerie Orwellian warning, and those who believe that the more cameras there are, the less crime there will be. Studies, though, suggest that CCTV has specific and narrow uses.

Obviously, it helps catch people who have committed an offence, after the event. CCTV networks, though, have no noticeable impact on crime rates according to several reviews in the US and UK. The UK is the most monitored nation in the world, but as a Home Office study in 2005 concluded, there was no statistically significant reduction in crime, once other variables like seasonal and national trends, and other police initiatives, were factored in.

While CCTVs are not easy to isolate as a determining factor in crime control, they are demonstrably effective in some contexts. They can reduce some kinds of disorder and petty crime, particularly in car parks and public transit. Micro-level analyses of aspects like environmental features, camera line-of-sight, enforcement activity, and camera design suggest that the power to deter crime depends greatly on how the CCTV sites are chosen, and police operations designed.

The downsides are well known. The more mundane footage there is, the harder it is for police to sift through. There is often a displacement effect — the presence of a camera pushes the crime off-stage into other areas, or prompting criminals to change tactics in pursuit of the same ends (ie, rather than carry out a drug transaction on the street, arrange online and deliver). What's more, CCTVs can be gamed. In Mumbai, the police has found out that criminals apply toothpaste or flash a torchlight at the lens, or cover up with helmets and burqas, or even steal the digital video recorder in the CCTV. These cameras have to be constantly maintained. "Many believe that CCTV installation is a one-time investment, but it needs to be serviced to yield results," says S. David, who runs an electronics shop and sells CCTV cameras in Chennai's Ritchie Street.

If there is no overwhelming impact on crime prevention, why are India's security forces investing so heavily in CCTVs, and is it worth the inevitable tradeoff with privacy? More worryingly, it is doing so without any comprehensive regulation on their use.

Before this technology of databases and recording, "we seldom had situations where a police official or private detective was trailing you all day, recording your movements, which is more or less the situation with CCTVs now," says Pranesh Prakash of the Centre for Internet and Society. "Yes, you're in a public space, but that doesn't denude you of privacy".

But as Farhad Manjoo, a prominent tech blogger in the US, pointed out, the benefits outweigh our fears about privacy. "When you weigh cameras against other security measures, they emerge as the least costly and most effective choice. In the aftermath of 9/11, it's impossible for you to get into tall buildings, airports, many museums, concerts, and even public celebrations without being subjected to pat-downs and metal detectors. When combined with competent law enforcement, surveillance cameras are more effective, less intrusive, less psychologically draining, and much more pleasant than these alternatives," wrote Manjoo in Slate.

What we need is public oversight over the surveillance apparatus — in other words, we need to watch how they watch us. If there is clear respect for the principles of proportionality, accountability and transparency, "there need not be a conflict between ethical and effective use of these cameras," says Ramachandran.