His style was now set, it would be anti-surveillance, turning the camera from a device that focuses in on the most important part of the frame, to one that captures the wider view and pushes the viewer to seek out the significance of the picture.

BBC: Paul Graham: Photographs 1981-2006

In July, a surveillance camera caught a man throwing an incendiary device onto the building that damaged part of the roof.

CNN: Spate of attacks near Ramadan trouble U.S. Muslims

Prosecutors also played a surveillance video of Hassoun, wearing a black hoodie, dropping the device into a trash bin at about 12:20 a.m. on Sept. 19, 2010 while people crowded the sidewalk and music blared from area bars.

NPR: Would-Be Chicago Backpack Bomber Gets 23 Years

Mr. Kelly said the department had been working with a security-and-surveillance systems manufacturer based in Britain, along with the London Metropolitan Police, to develop the device.

WSJ: Police Test New Scanner