Just Before Dawn (1946)

When his neighbour knocks on his door to say they are having a party in the house opposite, she doesn't actually invite "Dr. Ordway" (Warner Baxter) but instead asks him to come and treat a suffering diabetic. He helps out with the insulin only for the man to promptly collapse in a heap, dead, with only a dying phrase to help explain. The autopsy reveals the drug was poisoned, and so police inspector "Burns" (Charles D. Brown) suggests to the doctor that the best way to exonerate himself from any suspicion of complicity is to do the detective work himself. His investigations prove quite perilous, though, and as the body count starts to mount we are introduced to a couple of sinister characters and begin to see the a pattern of greed and duplicity. "Ordway" must use his guile to outwit his unknown antagonist at some considerable risk to himself (and his eyesight) as he tries to entrap the culprit. This is quite good fun with Baxter delivering engagingly as he tests and tricks his suspects. There are no shortage of them, and the supporting cast provide workmanlike efforts as he whittles down the suspects and tries to stay on the right side of the crematorium wall. The denouement is all rather rushed and the audience is well ahead of the curve as he follows the clues, but it's still quite a watchable short drama.