It was one of Boris Johnson's election pledges to bring in mobile weapons scanners and knife detector arches and today saw them appearing at tube stations and on London's streets as a very public and visual response to the knife crime murders of the past week.

As one astute Londonist reader has pointed out, where was the swift resort to "in your face" policing after the unfortunate teenage girl was allegedly covered in lye and gang raped by Bigby and his mates?

Male, teenage suspects have now been charged in the respective murders of Steven Bigby and Jimmy Mizen.

Image of Banksy's Hoodie at the Cans Festival courtesy of Amanda Farah's Flickrstream.