I thought exactly the same about controlling a millilitre of water. You could straight up behead people on sight and leave basically no trace at all - just a suspiciously clean cut
but you definitely wouldn't leave an evidence trail.
Yes, officer. It's the second victim that died from a Dr. Pepper can randomly falling on their head today. As the two other ones yesterday and the two the day before yesterday...
I was thinking of summoning a can inside the head, heart, or throat from across the entire country, but I like the idea of a mystery Dr. Pepper drowning.