Martinez also hammered her Thursday on other changing stories. Arias claims she injured her right finger when Alexander beat her months before the killing, even once holding up her crooked digit in a dramatic display for jurors in previous testimony.
However, Martinez noted Arias told a detective after her arrest that she injured her finger on the day of Alexander's death when one of the intruders attacked her.
"You gave him a different story," Martinez said pointedly.
"Yes," Arias replied.
"Then you testified about it in this court and you gave us another story of how this happened, right?" Martinez asked.
"No," Arias said defiantly.
Martinez noted that Arias made no mention of injuring her finger in a fight with Alexander in her journal where she kept pages of intimate details from her life.
"And no one knew about this supposed or claimed injury to your finger until after you killed Alexander, right?" he said.
"That's right," Arias replied.
Prosecutors say Arias planned the killing in a jealous rage, savagely attacking Alexander in his home.
Alexander's friends say Arias is lying about her contention that he had sexual desires for young boys, and that he was physically abusive, and no witnesses have testified of any previous violent behavior or his interest in children. Authorities also have said they did not believe Alexander owned a gun, and there has been no testimony to back up Arias' story that he kept one in his closet.
Arias' grandparents reported a .25 caliber handgun stolen from their Northern California house about a week before the killing — the same caliber used to shoot Alexander — but Arias claims to know nothing about the robbery. She says she brought no weapons to Alexander's home on the day she killed him.
Prosecutors must prove she planned the attack in advance to secure a first-degree murder conviction and a chance for a death sentence.
Of the day she killed Alexander, Arias said she only remembers shooting at him, putting a knife in the dishwasher and disposing of the gun in the desert as she drove from Arizona on her way to Utah. And she immediately began planning an alibi "to "throw the scent off for a little while."