Facial recognition and spotters part of operation at Emirates that involved a dozen incidents and two arrests The concourses are silent when, deep in the Emirates Stadium’s bowels, Chief Inspector Pete Dearden’s briefing begins. Arsenal’s 4.30pm kick-off against Chelsea is still hours away but the fixture carries significance as a London derby and because the Premier League champions are hosting a realistic challenger. Dearden is a senior officer in the Metropolitan police’s public order comman…