Spot the Loony!

Peter Sutcliffe [the Yorkshire Ripper] told police that in 1967, at the age of twenty, he had heard the voice of God speak to him as he worked at Bingley cemetery. He would claim that he had first heard that voice while digging a grave. He stated that the voice had led him to a cross-shaped headstone upon which were written the Polish words JEGO, WEHBY and ECHO. It was this same voice that had ordered him to kill prostitutes.
-crimelibrary.com

Harvey Carignan assured the policemen who arrested him in 1974 for multiple rape, mutilation and murder that they had made a mistake because the person they had arrested - himself - was: "An instrument of God, one who was acting under His personal instructions. Murder, rape and mutilation are all part of a Grand Plan. God is a figure with a large hood and you can’t see his face."
-casebook.org

A devout and obsessive religious upbringing as a child probably influenced the killer Herbert Mullin to start murdering people in the USA in 1972. Voices told him what to do as he shot four young boys to death in a park at Santa Cruz. When his murder count reached thirteen the police caught him and were no doubt highly impressed by his claim that he had received telepathic messages from God, and he was in fact the "saviour of the world" who had just saved the world by shooting people.
-casebook.org

On January 23, 1972 [Joseph Kallinger] branded his oldest daughter for running away. He was arrested for child abuse and found incompetent to stand trial. By mid-1974 he was constantly hearing voices from a floating head that followed him around. God also spoke to him and told him to kill young boys and sever their penises. Eager to comply, Joe enlisted his 13-year-old son, Michael, and proceeded to torture and murder a nine-year-old Puerto Rican youth. Their next victim was one of his own children, Joe Jr., who had previously accused him of abuse.
--Slaughtered in the name of God

During a jailhouse interview last month, [Christopher] Turgeon said he has no regret or remorse and truly believes what he did was right and ordered by God. "I can't question God's methods," he said. "I just obey."
-A Killing in God's Name

"God told me to do it."
-Deanna Laney, on bludgeoning her children to death

"Allah ordered us in this religion to purify Muslim land of all non-believers, and especially the Arabian Peninsula where the Ke'ba is."
-Osama bin Laden

"God told me to strike at al Qaida and I struck them, and then he instructed me to strike at Saddam, which I did, and now I am determined to solve the problem in the Middle East."
-George W. Bush, speaking to Palestinian PM Abu Abbas