Made at a time when Scotland Yard could have a simply frightful time catching a smash and grab raider, apart from anything else; when the old hands can remember criminals whole families and what prisons they are/were in; when an anonymous caller gives a tip off and all Scotland Yard swings immediately and earnestly into action; when crimes were recorded on index cards and a whole army of men employed to manually cross check everything; when department store sales clerks spoke with an Oxbridge accent; when everybody smoked; when kids thought it was wizard to have lemonade (with straws) at birthday parties; when your wife worried about you; and when you called your quarry 'chummy'...
This is so cheesy by modern standards that it's almost a self-parody - almost, but not quite. (In fact I did burst out laughing when Jack Hawkins was speculating about 'chummy', with a anguished look on his face). Nevertheless, it still manages to tell a great story and has some glorious outdoor photography of the period, especially central London. Hawkins is great, playing his role with dogged determination and typical British resolve.
Another thing that strikes me watching these old b/w films is just how brilliantly even the minor characters are played. Watch out for Meredith Edwards - the garage owner in Wales, and particularly the flawless understated acting of the woman in her only scene who offers Hawkins a cup of tea, but he declines).
Great fun from a long gone era and highly recommended for many reasons including, but not limited to, the story.