The mother of a man who stands accused of murdering 12 people in a movie theater gun rampage has begged prosecutors to stop pursuing the death penalty, terming their legal case a 'quest for death'. Arlene Holmes, whose son James, 27, opened fire at a busy screening of Batman film The Dark Knight Rises in Aurora, Colorado, also insists that she and her husband Robert 'were good parents'. The Holmes family claim that mental illness is to blame for the murder spree, which left 70 injured as well as the 12 fatalities. Scroll down for video . Begging for his life: Arlene Holmes prayed for prosecutors to stop their 'quest for death' in seeking a death penalty punishment for James Holmes, left, who killed 12 people in Aurora, Colorado, in 2012 . 'Good parents': Holmes and her husband Robert, pictured above this week, have said the killings are the fault of their son's mental illness . Massacre: James Holmes opened fire at the Century 16 movie theater in Aurora, Colorado, killing 12 people and injuring 70 who were watching Batman film The Dark Knight Rises . They believe their son was having a psychotic episode during the killings, and should therefore be spared death in his trial, which is due to begin on April 27. Mrs Holmes begged the prosecutors not to seek the death penalty in an entry in her prayer book, which she published earlier this month and is selling for $15. Her prayer for the prosecutor reads: '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.' She also also gave an interview on the book to the Del Mar Times local newspaper from her home in Rancho Penasquitos, California, saying that offering her son a plea deal would prevent a painful trial. 'Good parents': Holmes suggested that she and her husband Robert, right in the above image, had not done anything wrong . She said: 'This would all come to a grinding halt if [James] could plead guilty, and the DA would accept the plea for life without parole.' Mrs Holmes also defended herself and her husband from charges that they contributed to the massacre. She said: '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.' Mrs Holmes did, however, say the couple feels guilt 'that we didn’t recognize he was ill and needed treatment.' On sale: Holmes published a book of prayers for people involved in the murder, which sells for $15 . According to her, the killing was completely out of character, and the first time she was aware of her son having anything to do with guns. She told the Del Mar Times: 'Our kid was quiet, compliant, obeyed all the rules. He never bothered anyone, he never harmed anyone... We never owned a gun and he showed no interest in guns.' This is the first time Mrs Holmes has been interviewed since the killings in July, 2012. The couple had remained entirely silent until last December, when they wrote a letter to the Denver Post newspaper, insisting that their son 'is not a monster'. Other parts of Holmes's book deal with her feelings at each stage of discovering her son was responsible for the massacre. In an entry from Jan. 12, 2013 called Preliminary Hearing Memories, she wrote: 'What were you thinking, Jim? And what are you thinking now? Praying for Jim in jail; please don't commit suicide. 'You lived so that we could understand you and others could study you and learn to prevent future tragedy.' In another from March 22, 2013, titled Memories, she again defended her son. She wrote: 'My son never harmed anyone. 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.' Mrs Holmes writes in the book that proceeds will be donated to mental health services, not to her son or his case. But victims' families have questioned the timing, as defense attorneys have asked a judge to move the proceedings, saying pretrial publicity has made many prospective jurors biased against Holmes. 'I can only think this is some kind of ploy. This is some type of strategy cooked up by the defense to try to save someone's life,' said Tom Sullivan, whose son Alex was killed in the shooting. 'Ploy': The father of victim Alex Sullivan, pictured, described Holmes's book as a 'strategy cooked up by the defense' Holmes' mother's thoughts and apologies mean little to him, he said. 'As far as people I think about on a daily basis, they are so far down the list it's not worth mentioning.' Neither Holmes' parents nor an attorney representing them immediately responded to requests for comment. Mrs Holmes said her son's defense team had no knowledge of the book. 'This book is being published to raise awareness of the immorality of the death penalty and the futility of seeking justice through execution,' she writes. A spokeswoman for District Attorney George Brauchler declined to comment on the book, citing a gag order that prevents those involved in the case from talking about it. But in court filings released Monday, prosecutors, arguing against a change in venue, wrote that the one thing jurors remembered most clearly so far was their sympathetic letter to the Denver Post.
Arlene Holmes, whose son James killed 12 in massacre, has spoken out . Prayed prosecutors would abandon death penalty for 2012 killings . Trial for 27-year-old's shooting spree in Aurora, Colorado, begins in April . Holmes also insisted that she and husband Robert are not to blame . Believes her son is mentally ill and as such should not be put to death .