Law & Order: UK

As the last person to apparently have seen Finn Tyler alive DS Sam Casey is suspended from duty pending a full investigation. Convinced of Sam's innocence Ronnie does some sleuthing of his own, with DI Wes Leyton getting hands on with the investigation. Discovering that CCTV footage of Tyler in his cell has gone missing, this in turn leads him to discover a pact made by the bereaved relatives of the train victims and to the real killer.