"I want to report a murder."
"Who was murdered?"
"I was."
This is how D.O.A. opens, so it spoils nothing to tell you that this is the story of a CPA named Frank Bigelow (played by Edmond O'Brien) who is poisoned.
If, like me, you happened to see the 1988 remake of D.O.A., starring Dennis Quaid and Meg Ryan) this one is...
How shall I put this charitably?
...better.
Enjoy!
(This YouTube lists the movie as 1950; its release was actually 1949.)