Won't bad karma cause a chain reaction?
Your bad Karma does not cause bad Karma for others. If another person gets a mindset to kill, it's not a result of your bad Karma. It's a result of his own aversion and volition. But your bad karma can place you at the wrong place at the wrong time.

ex: A crocodile might attack anyone who gets into the water. Your bad karma can place you at the river when the crocodile is waiting to grab a meal. 
Coconuts fall down from coconut trees whether you killed someone or not. But your bad Karma can place you under a coconut tree when a coconut is falling down.