Armed police arrested three men in Barking after a business owner was threatened with a firearm.
Officers were called to the incident in River Road on Thursday.
CCTV operators heard over police radio that the suspects had then made off in a silver Peugeot and were heading towards Barking Town Centre.
They used cameras to track down the vehicle and inform officers.
After managing to stop the vehicle, armed police recovered a gun and arrested the trio for firearms offences.
Cllr Margaret Mullane, cabinet member for enforcement and community safety, said: “The use of CCTV is crucial in helping us track down individuals who are breaking the law and need to be brought to justice.
“Without the help of cameras they could have escaped so this was a great team effort between the council and police to ensure they were caught and arrested.”
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