Just my two cents. Logistics of current tech aside, I think it is a bit premature to make such specific laws. I am not a lawyer, but I could see using existing laws to prosecute a person or company that builds something with the intention of harming others, assuming it was not sanctioned by a government to do so. If the device malfunctions and accidentally harms someone, then I would expect the existing legal framework to deal with that as well. If your Tesla gets hacked by some kid and your car mows people down there would be an investigation and if a root cause is found, the existing legal framework should be able to deal with this. If an interstate fuel pipeline control framework is hacked and fuel supplies are shut down ... well you get the picture, this is already a potential risk in all current tech. So bring on the Ninja robots and just make sure nobody can hack into it and that it has fail-safes in place to prevent unauthorized harm. Authorized being the level permitted in a martial arts tournament or that of a personal security detail... Perhaps another angle of this would be what type and amount of liability insurance you are required to carry for such a device especially if it is allowed outside of a very controlled and secured environment.

I could see laws and more specifically rights for systems that become sentient. If something becomes self aware and/or a life-form then I think we would need to give it protections not afforded machines. [1]

[1] - https://www.youtube.com/watch?v=vjuQRCG_sUw