Just Before Dawn (1946)

Some new neighbors of Dr. Ordway call on him one nigh as the man of the house is not feeling well. Turns out he's a diabetic and missed his insulin shot. Warner Baxter gives him his shot, but moments later the man is dead.

After that introduction the police allow Baxter a free hand t work as their agent in solving the crime. The investigation leads him to a funeral parlor where he director Martin Kosleck has an interesting sideline in plastic surgery for criminal types.

Baxter takes a potentially fatal gamble in finding he final solution. Watch and see what i mean.