CENTENNIAL, Colo. — When the younger sister of Colorado theater shooter James Holmes visited him in jail nearly two years after the attack, she no longer saw the loving brother who protected her when they were growing up.

“His whole demeanor seemed different,” Chris Holmes said of the May 2014 visit. “His eyes, they were almost bugging out of his head.”

Chris Holmes, 22, became the first in her family to testify at her older brother’s death penalty trial Monday, saying in an effort to spare his life she did not believe her brother was mentally ill growing up, but she also did not know how to recognize the signs.

Defense attorneys said they plan to call more witnesses today who can testify about Holmes’ character as jurors consider whether he should serve life in prison without parole or be executed for killing 12 people and injuring 70 others during a crowded midnight movie in July 2012.

Expected to take the stand are Holmes’ parents, Robert and Arlene Holmes, who have been sitting behind him in the courtroom every day of his 12-week trial.