This question is actually one from a roleplay. It is a school assignment in our mock trial class to come up with a murder case then to use it for trial. My case is a poisoning case.
This victim ingested a liquid poison from a vial, drank all of it. Experienced immediate symptoms.
Experience immediate side effects:
~Bleeding from mouth
~Head aches, possibly from swelling or shrinking
Death was almost instantaneous.
What poison could have done these things?