

For once, I don’t think that particular charge is entirely inconsistent with the dictionary definition.
He’s accused of killing a member of the public in the hope of frightening everyone else in that person’s position into taking some kind of action.
I think the law says something about killing for a “political purpose”, with the goal of changing some kind of public policy or behaviour. That’s not an unreasonable interpretation of what happened, I think.
Unfortunately that means they get to use the laws which were written to deal with mass murder and bombing public spaces, which I don’t think is particularly appropriate but doesn’t seem out of line with the law
How did you calculate that? The question didn’t even mention a specific speed, just “near the speed of light”.
The kinetic energy for a grain of sand near the speed of light is somewhere between “quite a lot” and “literally infinity” (which is, in a sense, the reason you can’t actually reach light speed without a way to supply infinite energy).