Arias herself testified for 18 days, ABC News reported Tuesday.
The prosecution immediately called a psychological expert, Dr. Janeen DeMarte, who rejected testimony by defense witnesses that Arias suffered from post traumatic stress disorder.
Arias admits to killing her ex-boyfriend Travis Alexander in June 2008, but claims it was self-defense. She says she shot him after he became enraged when she dropped his camera in the shower, but doesn't remember anything after that. Alexander's' body was found stabbed 27 times, his throat slit and a bullet in his head.
Under questioning by prosecutor Juan Martinez, DeMarte said Arias exhibited signs of borderline personality disorder, including unstable personal relationships, inappropriate anger and suicidal thoughts.
The trial began in January and is expected to continue for several more weeks before going to the jury.