(AP) - Prosecutors urged jurors Tuesday to dismiss a murder defendant's assertions that an angel who looked like Olivia Newton-John ordered him to fatally shoot a co-worker's husband outside a preschool. They say Hemy Neuman was not delusional or insane and had planned the killing for months. Neuman fell so hopelessly in love with Andrea Sneiderman, whom he supervised at General Electric, that he believed he was the father of her two children and that the only way to protect them was to kill Russell Sneiderman in November 2010, Neuman's attorney Doug Peters said during opening arguments. "He thought Sophia and Ian were his children and that Rusty Sneiderman was a danger to them," said Peters, who contends his client is not guilty by reason of insanity because he couldn't tell the difference between right and wrong at the time of the killing. Neuman believed an angel told him to pull the trigger, said Peters, who didn't give many details about the vision. He said only that Neuman told mental health experts that he killed Sneiderman "because that's what the angel told him to do." Prosecutors, though, urged jurors to reject the insanity claim, arguing the 48-year-old Neuman meticulously planned the killing so he could be with Andrea Sneiderman. Prosecutors said Neuman will also claim he was visited by a demon who sounded like Barry White. Sneiderman was killed shortly after dropping the couple's 2-year-old son off at the center in Dunwoody, an affluent suburb north of Atlanta. A bearded man in a hoodie fired several shots and then hopped into a silver minivan and sped away. Tuesday's focus was on Andrea, who repeatedly rejected assertions that she and Neuman shared a string of "intimate relations" during business trips in the months leading up to the killing. "There was no affair," she exclaimed at one point. She said she repeatedly turned down Neuman's romantic advances, including an email that said "I love you and marry me." She said she felt like she betrayed herself for allowing him to hold her hand during one business trip. She defended herself for sending emails expressing thanks for gifts such as roses and excitement over his suggestion to go to a nightclub during a business trip in London. I can't control what he said to me. I can only control what I said to him," she said. I was doing the best I could to keep my job and keep everything together. At some points choking up and other times flashing anger, Andrea said she was under Neuman's "manipulation," and that his increasing role in her life strained her relationship with her husband and her friends. But she bristled at accusations she was involved in anything inappropriate. "I admit to caring about Hemy Neuman," she said at one point. He managed to get me to care about him. He managed to manipulate people around him to feel bad for him. She also said she believed he was stable. Neuman faces life in prison without parole if convicted. He'd be turned over to the state mental health system if found not guilty. Neuman's attorneys tried to portray Neuman as a brilliant but troubled child who was constantly in fear of his father, a Holocaust survivor who was wracked with guilt because he was able to escape the death chambers at Auschwitz while 11 other relatives died. Neuman later graduated from Georgia Tech and bought a pricey home in a Cobb County subdivision after landing a job as a high-ranking manager at GE, where he made $180,000 a year and supervised 5,000 engineers and a $800 million budget, prosecutors said. Neuman hired Andrea Sneiderman in early 2010. She decided she needed to earn more money because her husband, a 36-year-old Harvard-trained entrepreneur, was having trouble finding steady work, attorneys said. They hit it off, and on work trips they would share long dinners, wine and occasionally romance, Neuman's defense team contends. Prosecutors say Neuman began planning Russell Sneiderman's killing after she rebuffed one of his advances. He bolted when Sneiderman, who couldn't recognize Neuman, stumbled upon him. Nine days later, prosecutors say, Neuman arrived at his office earlier than usual - at 5:36 a.m. - and then sneaked out a back door to avoid security cameras and to give himself an alibi. He drove to the Dunwoody Prep, shot Sneiderman four times and hopped in the minivan and tried to melt into morning rush traffic, they say. Neuman was returned to work a few hours later and was so callous about his actions that participated in the religious ceremonies honoring his victim, including visiting Sneiderman's house for a Jewish mourning ceremony, Geary said. He even went to Sneiderman's funeral and shoveled dirt on his grave, another Jewish end-of-life ritual, the prosecutor said. Peters said he'll argue throughout the trial, which is expected to last several more weeks, that evaluations from mental health experts who diagnosed Neuman as bipolar and concluded he has a delusional disorder back his arguments that his client couldn't tell the difference between right and wrong.