James Holmes called Gargi Datta His Girlfriend even though She corrected Him on many occasions. The two, graduate science students at the University of Colorado, had broken up by the spring of 2012, but they occasionally chatted online. She said she never had any inkling that her former boyfriend, James E. Holmes, was amassing an arsenal of guns, ammunition and body armor that he would use to kill 12 people and wound 70 inside a Colorado movie theater.

During the trial’s opening in late April, the district attorney leading the prosecution, George Brauchler, told jurors about an online conversation in which Ms. Datta tried to cheer up Mr. Holmes, who had been struggling in his neuroscience lab rotations. She told him to play video games. He told her he could not do what he really wanted because it was evil. She asked what he meant, and he told her, “Kill people, of course,” Mr. Brauchler said.