I was watching "The Terminator" (the first one) and I was thinking about it. Check out my pic by the way. Anyways, yeah so the Terminator comes back in time to kill Sarah Connor and prevent her from giving the birth to the savior of humanity. The Terminator is really rigid.
Even if a robot commits an act that can be seen as criminal, it never had the intentions to do so, or any intention whatsoever. Science fiction portrays many robots as being sentient, but until such a technology does come to pass, robots are only objects used to perform actions. For example, if a weapon is used to harm an innocent person, can you call that weapon evil? If it were used to protect the innocent, can it be seen as good? The tool used cannot be "good" or "evil", only the man who wields it. Something that does not have the capability of formulating its own intentions cannot be evil.
Robots are programmed to do what ever the programmer(s) want(s). Computers do exactly as they are told to do, though what they are told to do isn't always what the person intended to tell them to do. Robots aren't evil, only their creators can be. Evil, in my opinion is when a being knowingly and optionally chooses to do evil.