Mr Guard, who makes documentaries about crime and the homeless, was filming squatters entering a disused building through an open window at 10pm on August 1.
A security sensor inside detected the movement and the alarm was triggered.
The squatters fled but Mr Guard, a former electrician, decided to stay behind and turn off the alarm to save neighbouring families from the noise.
To do so he had to turn on the electricity in the building for a few seconds, to give him light, and then turn it off.
Nine police then arrived in response to the alarm. When Mr Guard told them what he had done, he was arrested and held in a cell for six hours before being charged.
Film maker is taken to court for stealing 0.003p - at a cost of over £5,000 to the taxpayer
It beggars belief. Especially as they used 9 plods to arrest him.