Updated

As Jodi Arias' trial wraps up this week, the crux of a first-degree murder conviction — even second-degree or an unlikely acquittal — rests, in part, on the testimony of expert witnesses as jurors will no doubt grapple with the sheer volume of evidence, and struggle to come to grips with the defendant's ever-changing version of events.

Arias' unprecedented 18 days on the witness stand, too, will be at the heart of deliberations as the jury decides whether they believe her. One more witness is set to testify Wednesday.

Closing arguments will be Thursday and Friday.

Arias faces a possible death sentence if convicted of first-degree murder in the 2008 killing of her lover in his suburban Phoenix home. Authorities say she planned the attack on Travis Alexander. Arias says it was self-defense.