Sex offenders on trains are escaping justice because of serious issues with CCTV on the rail network, a BBC investigation has revealed. One woman who was sexually assaulted on a train told us she was "devastated" to be told that police could not trace her attacker because the incident was not captured on camera. In hundreds of cases of alleged sexual harassment or assault, British Transport (BTP) officers in England, Scotland and Wales say they struggled to gather evidence from CCTV footage collected from trains and stations. The Rail Delivery Group, which represents train companies, says the industry takes sexual harassment and assault cases "very seriously". File on 4 Investigates has also been told that BTP has no control over the maintenance of CCTV cameras on the rail and London Underground networks, and that there is no legal obligation on rail operators to have working CCTV cameras on passenger trains.…