Anyone Know this movie????

Hello, I'm taking a wild stab here, but when I was around 10 or 11, in 1968 , I saw a gangster movie on TV, and I have spent many hours trying to find the name of it. I know film noirs pretty well, so I don't think this will be a famous one. Someone who likes "Little Caesar" may perhaps know this movie.
What I remember is this: The main character usually wore a trench coat(big help, right?) and he had an arm in a sling later on in the movie. He kind of had the look of Alan Ladd...blonde, stoic....the movie is not "This Gun for Hire"...anyway, he was warned to not go out one night by a male friend...but he did anyway, and a car pulled up and machine-gunned him down. I think he was a good guy-maybe not a gangster....not like in "Little Caesar"... The last scene shows the male friend in a upstairs window crying....maybe he set him up? I think a clock was sounding off when it happened. (the movie is not "The Big Clock". I don't know, I was so young....maybe my mind played tricks on me...but that is how I remembered the movie.
Another movie I remembered as a kid, was a guy hanging from a building and another guy goes to help him up..and it is this other guy that actually falls to his death....I was so happy, when I was about 22 yrs old and went to see "Vertigo", and...I found the movie! So it IS possible, but this movie is now going on 38 yrs in the search....I hope someone out there may have a clue....My Email is [email protected]