[faster]

I recently read a book where the killer convinces victims (via hypnosis) to swallow their tongue, which blocks the airway and suffocates them.

Decades ago, there was an episode of Hawaii-50 where the killer used bullets made of ice, so there was no evidence to work with.

[lisper]

> bullets made of ice

This was one of the topics on the very first episode of Mythbusters:

https://www.dailymotion.com/video/x6pcm0l

[01100011]

If you wanted to kill someone with a bullet made of ice, or, IMHO even cooler, dry ice, you'd forgo a conventional cartridge, which would contaminate the scene with gunpowder anyway.

You'd use something like compressed air. You can reduce the instantaneous pressure delivered to the projectile which helps fix the melting problem. You'd want to chill the barrel a bit, but some melting might be good there as long as the water doesn't refreeze in the barrel and stop successive rounds. Basically you're making a potato cannon that shoots ice.

Bonus for freezing the water/co2 out of the air itself. You wouldn't even need to carry ammo.