Leila Marino

Leila Marino was an individual who was involved with Abstergo Industries before Desmond Miles was captured and brought in to be used as a new test subject in the Animus. She died under mysterious circumstances. It is also said that she had a romance with Subject 16 and might have also been a close friend to Lucy.  

In Lucy Stillman's e-mails, she asks Vidic about Leila a lot. The only explanation she can get is "she killed herself." This hints at the possibility that she was an Assassin and was silenced by Abstergo. There is also the theory that she and Subject 16 became lovers and committed suicide together in order to leave the glyphs written in blood, but this theory is unlikely due to the fact that Leila died in 2007, while Subject 16 was held captive shortly before Desmond. This is also unlikely due to the fact that Subject 16 used his own blood to draw the glyphs on the bedroom wall and stated that Lucy witnessed him raise the knife and kill himself. Another theory is that Leila worked in the Abstergo's underground facility at the Denver International Airport during the satellite malfunction with the Piece of Eden in 2007, which is also the year she died.

In the e-mail mentioning her relationship with Subject 16 ("Neumann"), Vidic says, "Don't dip your pen in the company ink," which would contradict the theory that Neumann is Subject 16.