Both Jack Warner and Richard Widmark play policemen who get killed in a feature film and then go on to play the same character in a TV series, Jack Warner in "Dixon of Dock Green" for the BBC and Richard Widmark in "Madigan" for Universal TV.
As PC Dixon leaves the police station to go on his beat he picks his cape and puts it over his shoulder. A short while later he's seen on his beat but his cape has disappeared
When car 5-D makes a turn at supposed high speed, just after PC Mitchell says "There they are", a woman and two children on the pavement at the left are also walking slightly faster than usual.