Horrors of the Black Museum (1959)
Thought I'd give this another look as I hadn't seen it since the mid-60s when it must have been a second feature as I certainly wouldn't have seen it in 1959, and wouldn't have paid to see it as a main film.
Quite creaky now, BUT the binoculars murder still haunts me, especially IF it was based on a real crime from the Police's Black Museum, which does exist somewhere in London.
Even now, with binoculars have owned for a number of years, I will still turn the focussing knob before I put them up to my eyes.