This is one of those thrillers that is in no way a whodunnit as it becomes evident very early on that the killer is who you think it is going to be.
But that is not sloppy film making, it is entirely deliberate, for the mystery here is not who is the killer, but will he get away with it, and what will happen to our hero?
It is a well plotted piece, and, oddly, based on a true story.
[see Jack The Stripper - https://en.wikipedia.org/wiki/Hammersmith_nude_murders]

Some fine performances from good, steady actors, all giving well rounded characterisations, especially Barry Foster and Billie Whitelaw.

The general feel of London in the early 70s is well presented, and the locations are well chosen to give the overall viewing of the film a very satisfactory glow.

Not one of Hitchcocks classics, to be fair, but still a great film and one that will certainly entertain.