I thought I recognised the chap playing Owen, the homeless man, but when I looked him up, I realised I didn't know him. He's the ABSOLUTE SPITTING IMAGE of his father - Tim Roth.
Didn't see this but for father and son likenesses, you can't beat Alun Armstrong and his son who was in that acclaimed drama last year with Sarah Lancashire....happy valley I think it was called.
Askyourgran - we have the same problem as you, turning up the sound a lot, then having to turn it down again, love Silent Witness though, brilliant plots