Corrected entry: Throughout the episode, we see Angelus show up on a security camera in the basement. But it is a well known fact that vampires do not show up on security cameras. It's been established several times in the show.
Bishop73
15th Oct 2011
Correction: It's been well established in the Angel series (same as the Buffy series) that vampires DO appear on cameras (and photographs) since cameras work similar to the way the human eye works. Electronic security systems don't pick up vampires, since they don't have body heat, but surveillance cameras are not the same as a security system.
Bishop73