China Arnold of Dayton, Ohio, who was convicted last week of killing her 28-day-old daughter in a microwave oven was spared the death penalty and sentenced this afternoon to life in prison without parole. Prosecutors say the 31-year-old intentionally put Paris Talley in a microwave and turned it on after a fight with her boyfriend in 2005. Medical experts testified that the baby died quickly after her temperature reached between 107 to 108 degrees Fahrenheit. They said she probably was in the microwave for more than two minutes. "She died because she was overheated," said Dr. Marcella Fierro, retired chief medical examiner for Virginia. "She was cooked." China was tried twice before for the crime: Her first trial ended in a mistrial. She was found guilty in the second, but an appeals court reversed the conviction.