 John Glennon had been pretending to paint a mural in the sterile area between A and B wings which placed him in a position to see and hear what happened in the forecourt.Upon hearing the announcement over the prison Tannoy system that Wright and Green had been called for their respective visits, Glennon gave a pre-arranged signal to his two waiting accomplices.They moved into position at the A wing turnstile; Glennon ran into the canteen and he mounted a table situated beneath a window which gave him a clearer view of the block forecourt.