How good are CCTV cameras at preventing crime?

Dozens of CCTV cameras at Sydney Airport didn't stop a man being killed in broad daylight a few weeks ago, so how good is CCTV at preventing crime?

There are dozens of CCTV cameras at Sydney Airport, but despite this 'high security', a man was killed in broad daylight a few weeks ago. If having CCTV around doesn't stop murder, what can it actually do?—Frank

Ever feel like you are being watched? In shops, train stations and airports across Australia, CCTV cameras are keeping tabs on you. Yet CCTV did little to prevent a man from being bludgeoned to death with a metal pole at Sydney Airport last month during a fight between the Comanchero and Hells Angels bikie gangs. So what went wrong?
In this age of hi-tech, it may be our expectations of CCTV technology are too high.
"People always expect that CCTV is going to do more than it's actually designed for," says Dave Brooks, a CCTV expert from the Security Research Centre at Edith Cowan University (ECU) in Perth, Western Australia
"We tend to look at CCTV as a detection tool, but there's no real detection going on."
In reality, says fellow ECU researcher and expert in intelligence and security, Jeff Corkill, today's CCTV systems still rely on their human operators. And humans are… only human.
The human side of CCTV According to Corkill, it is possible to improve operator surveillance by recognising and playing to the limitations of human biology.

"Active surveillance is an intellectually demanding task. It requires you to sit behind a screen and focus intensely. Really, 30 to 40 minutes is the maximum you can monitor effectively what's going on in a very complex environment."

Corkill says for dedicated surveillance, operators can really only focus on between 1 to 2 monitors at a time. A good operator must also have the ability to differentiate between colours, pick up on motion and speed, recognise patterns and anomalies, and have a good memory.

They must also have good observation skills, including the ability to scan, focus, and make use of their peripheral vision, and have access to good intelligence information.

"A good operator who understands what's going on in the environment can detect individuals who are preparing to commit crimes, intervene and prevent the crime from being committed," says Corkill.
"You might have an operator in a control room with a couple of hundred cameras. They could have up to 20 or more screens to monitor," says Corkill.
"They could also be manning a phone and other things. In this case they are not necessarily going to see the subtle behaviours that will alert them to an incident starting to emerge."
That's where the development of new technologies such as 'intelligent CCTV' may help in the future.
"There's a lot of work to try and develop algorithms that, say, can detect when a person is moving in the opposite direction to the way everyone else is moving," says Brooks.
"This could be particularly useful in airports to detect if people are trying to move back into the aircraft."
Other technology is being developed that can detect objects like bags that have been left for a long time in the same place, or abnormal behaviour like standing too close to the platform at a train station.
But at the moment these new technologies are still a long way from being intelligent says Brooks.
"It's hard for a computer to pick out individual people and to translate the movement of blocks of pixels into real people. And in an environment like an airport terminal where there's lots of visual noise, lots of people moving about and people sitting still for long periods of time, it's almost an impossible task."
Biometric technology such as face recognition may be another surveillance option.
"Face recognition is out there, but it's still very easy to defeat," says Brooks.
Firstly, you have to have an extensive database and a controlled environment where people are face on to the camera.
"And your attacker could just put sunglasses on or say, in the case of a bikie, trim their beard off and thus destroy the ability of these systems to recognise a face."
So for the moment it seems we'll have to keep depending on the skill of our operators.
"I think that that will be the case for the next 20 years," says Brooks.
Corkill agrees: "CCTV in itself doesn't catch criminals. It doesn't have arms like a human and it doesn't reach out and grab them."


The human side of CCTV According to Corkill, it is possible to improve operator surveillance by recognising and playing to the limitations of human biology.

"Active surveillance is an intellectually demanding task. It requires you to sit behind a screen and focus intensely. Really, 30 to 40 minutes is the maximum you can monitor effectively what's going on in a very complex environment."

Corkill says for dedicated surveillance, operators can really only focus on between 1 to 2 monitors at a time. A good operator must also have the ability to differentiate between colours, pick up on motion and speed, recognise patterns and anomalies, and have a good memory.

They must also have good observation skills, including the ability to scan, focus, and make use of their peripheral vision, and have access to good intelligence information.

"A good operator who understands what's going on in the environment can detect individuals who are preparing to commit crimes, intervene and prevent the crime from being committed," says Corkill.