Scopolamine Suicide.
Just blow it at their face in powder form and give them suicidal instructions. Don't even need to leave any fingerprints.
Edit: Just learned about White Snakeroot. Pretty interesting, seeing as the root itself has medical purposes when turned into a tea or poultice.
spider ....australian??
But of course....
He is a huntsman ( not poisonous like the funnelweb or red back)...but more sinister looking.
He is the cause of more deaths than the other two. He likes to live in cars and often causes drivers to crash with the fright of his appearing at unexpected moments.