Hi @opmga,
Did media told you to think about robots like the killer machines in the terminator? :)
Yes, we can create machines like those but they will only kill or destroy if they have to follow our instructions, if we program them to do so.
If we ever create a multi purpose AI, than it will overgrow us in everything in a very short time. It won't be driven by money or manipulated by fear, neither will it have desires or doubts. It will know what and when to do to achieve something. Something we have no chance to understand.
As I see, more intelligence equals less desire to harm other beings.