UK Alcatraz Escape

In the UK press it was called the British Alcatraz escape. The inmates Matthew Baker and James Whitlock used dummies to trick jail guards at the out of date prison Pentonville in London. Matthew Baker was back behind bars on Wednesday and James Whitlock was  in his cell again on the Saturday. they had escaped from the cell block on the previous Monday. The week leading up to the break their had been riots on the cell wings. The two inmates took a gamble that their cells wouldn't be checked for a long time. They then used sheets to get over the 25ft outer wall.
How could this escape happen?  In a later post I will talk about this and what can be done to stop these escapes happing again.