An Aurora man who sprayed lighter fluid on his 3-year-old niece and then set her on fire because she was bothering him while he was listening to music pleaded guilty today to heinous battery and was sentenced to 17 years in prison. Raymundo Herrera, 19, of the 1200 block of South Grove Street pleaded guilty but mentally ill in a plea agreement, said Kane County Assistant State’s Attorney Lori Schmidt.