I've been studying ninjitsu for quite a few years now and to tell you the truth, it's been one of the better styles that I've come across. As far as killing goes, ninjitsu is more of a technique to evade...not kill. The chinese word "ninja" or "nin-sha" is actually pronounced "shinobi" in japanese which refers to espionage. Their job wasn't to assassinate or murder, but collect information and sabotage operations. So in truth, all martial arts techniques are "killing" techniques no matter what the teachings are. It just depends on how you use it. If you want to learn any style of martial arts, you need to first research it. Find out where it came from, how it was traditionally used, and what it's implications are. Please don't use biases/prejudice thoughts, rumors, or stereotypes to determine your choice.