We believe from his gestures that he is giving us a literal copy of acts he has seen performed.

Then, why pass over the gleam of infernal joy that lights his face after the whole is over?
It is as if he rejoiced over the deed, or at least found immeasurable satisfaction in it." "Perhaps it is still a copy of what he saw; the murderer may have rejoiced.

But no, there was no joy in the face of the young man I saw rushing away from this scene of violence.

Quite the contrary.

Mr.Gryce, we are in deep waters.