Continuity mistake: People (even the dogs) flying through the asteroid belt wear space helmets, but on the asteroids themselves, they don't.
Continuity mistake: The back page that has been ripped off is put in the envelope with the top part showing the right way up, but it was folded so if the ads side of the page was showing, either the middle part or the top part upside down would show.
Continuity mistake: The rotation of the feeding mechanism on the newspaper gun changes. It first spins counter-clockwise when Hermes starts firing, then it is shown spinning clockwise for the shot where Dwight takes over.
Continuity mistake: The comic books pages become blank when Cubert is ripping off the back page.
Continuity mistake: In the establishing shot of the science lab, Hermes' son is seen sitting next to a window made up of lots of panes. When he exclaims "My Manwich!", the window in the background is missing. (00:01:40)
Answer: You are thinking about episode 20 of series 2 - "Anthology of Interest I". She technically never kills anyone, but in the episode she ask a "What if machine" (one of the Professor's inventions) what would happen if she was more impulsive. The machine then shows the more impulsive Leela killing off the Professor to get the money from his will and thereafter killing Hermes, Bender, Scruffy, Cubert, Nibler, Amy and Zoidberg to cover it up. Finally she does something really impulsive with Fry.
Andreas[DK]