A woman who was convicted of killing her son by poisoning him with salt has been sentenced to 20 years to life in prison. Lacey Spears of Scottsville, Kentucky, was spared the maximum 25 years to life. The New York judge who sentenced her Wednesday said she suffers from a mental illness. He said the crime was still "unfathomable in its cruelty." Prosecutors asked for the maximum sentence, saying Spears sickened her son because she had a bizarre need for attention. The 27-year-old Spears was found guilty of force-feeding heavy concentrations of sodium through the boy's stomach tube.