[Kaderin Triste]

You look across the street at the neighboring apartment complex, and happen to witness a brutal murder. The murderer saw you. They stand there for a few moments, pointing a finger at you, moving it down, then back up to you. What are they doing?

They are most likely counting the apartments/windows to figure out which one you are in so as to come and kill you as well, eliminating any witness.
I recommend calling the cops immediately and finding a way to escape or a safe place to hide that isn't in your apartment...