Well there are many ways to kill someone but the first that came to my mind is using "Tetrodotoxin" (found in the <span>blue-ringed octopus and the puffer fish). It is capable of killing more than 20 humans in less than a minute. If you were to walk by someone and simply inject them with a small needle they would be paralyzed and dead in minutes. You could also slip it into a food of some sort.</span>
Nice, if you are in the more urban parts then it's definitely rarer but now with the orders, it is safer for animals. I remember once I saw a hawk in Oakland so it was pretty cool.