The mother of James Holmes, who is awaiting trial for the Colorado cinema shooting that killed 12 people and injured 70, has said she prays for her son's victims every day.

Arlene Holmes gave her first interview to the Del Mar Times this week, almost three years after the incident on July 20, 2012 in Denver. She has just released a book, 'When the Focus Shifts: The Prayer Book of Arlene Holmes'. It contains a collection of prayers from her personal journal, which she began following her son's arrest.

Among the prayers are those for each of those Holmes harmed. "Please, victims, please, feel my prayers. I pray for you by name," she wrote.

She also prays for those suffering from mental illness - Holmes eventually pleaded not guilty by reason of insanity in June 2013.

"My son never harmed anyone," Mrs Holmes wrote in March 2013. "People think he is a monster, but he has a disease that changed his brain...Praying for good men and women engulfed in psychosis and alone with their disease."

She said she wants to "apologise to the world" for her Holmes' actions, but "I don't believe Satan took my son. I believe mental illness exists. I'm praying for those who have been written off as evil."

She told the Del Mar Times that she and her husband feel guilty for not recognising Homes' illness sooner, however.

"Because so many people like to blame the parents if a child is mentally ill, we have to reaffirm to ourselves every day that we were good parents and good people, and this still happened anyway," she said.

Mrs Holmes is a strident opponent of the death penalty, which her son could face. Addressing the prosecution in her book, she writes: "I do not know what you have been through in life. I do not know why you want to pursue execution of a mentally ill man. But I pray for you, so that you will find peace in your life. I pray you will change your mind. Please stop this quest for death so you may focus on those who are alive."

"My basic feeling is it's immoral to have a state kill its own citizens, no matter what they did," she said in the interview. "I've always thought it was wrong. Now I've had a lot of time to think about it, and how much it hurts people."

She also believes helping those with mental illness is "starting to be a mission for churches in general", and her own church - Penasquitos Lutheran Church in San Diego, which Holmes also attended as a child - has been a huge source of support to the family. It was the first place she turned to when she heard about her son's crime. She remembers thinking: "Who can I call, who will drop everything and come and do something, help us cope? I knew if I called the church they would come."

Holmes' trial is due to begin in about a month's time.