Her lies and peculiar behavior, meticulously creating an alibi to avoid suspicion within hours of Alexander's death, have been at the heart of the prosecution's case.

NPR: Prosecutor In Arias Case Set For Closing Arguments

Arias has acknowledged trying to clean the scene of the killing, dumping the gun in the desert and working on an alibi, even attending a memorial service for Alexander before her arrest in July 2008.

NPR: Prosecutor In Arias Case Set For Closing Arguments