Colorado theater shooter's university psychiatrist expected to testify against him

FILE - In this June 4, 2013, file photo, Aurora theater shooting suspect James Holmes appears in court in Centennial, Colo. The person closest to the murderous thoughts of Holmes before he carried out his attack could take the witness stand the week of June 15, 2015, as the prosecution wraps up its case. Holmes' death penalty trial has revived unresolved questions about whether he could have been stopped. (Andy Cross/The Denver Post via AP, Pool, File) (The Associated Press)

FILE - This file photo released on Sept. 20, 2012 by the Arapahoe County Sheriff's Office shows James Holmes, who is charged with killing 12 moviegoers and wounding 70 more in a shooting spree in a crowded theatre in 2012. The person closest to the murderous thoughts of Holmes before he carried out his attack could take the witness stand the week of June 15, 2015, as the prosecution wraps up its case. Holmes' death penalty trial has revived unresolved questions about whether he could have been stopped. (AP Photo/Arapahoe County Sheriff, File) (The Associated Press)

FILE - In this July 23, 2012, file photo, James Holmes, who is charged with killing 12 moviegoers and wounding 70 more in a shooting spree in a crowded theatre in 2012, sits in Arapahoe County District Court in Centennial, Colo. The person closest to the murderous thoughts of Holmes before he carried out his attack could take the witness stand the week of June 15, 2015, as the prosecution wraps up its case. Holmes' death penalty trial has revived unresolved questions about whether he could have been stopped. (RJ Sangosti/The Denver Post via AP, Pool, File) (The Associated Press)

A psychiatrist who treated Colorado theater shooter James Holmes is expected to testify against him in his death penalty trial.

Prosecutors say they will call Lynne Fenton to the stand on Tuesday. Her testimony is among the most highly anticipated, as she was the mental health professional with the most access to Holmes' mind before he opened fire on a crowded movie theater, killing 12 and injuring 70. It could help answer lingering questions about what she did after Holmes told her he was having thoughts of killing people.

She told a campus police officer about her concerns in June 2012, a month before the attack.

A lawsuit against Fenton and the University of Colorado says she refused an officer's offer to place Holmes on a 72-hour psychiatric hold.