I remembered that Wynant had some shrapnel in his shin. They found it under the fluoroscope.
7 seconds sound clip from the The Thin Man (1936) classic radio play.
You can hear this line at 00:44:16 in the radio play.
Quote context
[...]
- He was down in the shop. It was his body that was buried there.
- Wynant's body? Yup. But they all said it was Rosewater's.
- What makes you so sure it's Wynant's body?
- The person who killed him counted on one thing: that all skeletons look alike.
- Sure.
- I remembered that Wynant had some shrapnel in his shin. They found it under the fluoroscope.
- Then he couldn't have committed those other murders.
- Wynant dead? Does Dorothy know?
- No. Nobody but you. I didn't even tell Guild.
- Why not?
- I want to lie low till I get the whole dope. I don't want to go off half-cocked.
- I'm going to get the real murderer.
- I've got an idea. Want to see me take him?
- Yes!
[...]