Riddle Me This!

Family Matters..... 

There was a family living in an round house. There was a mother, a father, a daughter, a son, and a maid. When the son was murdered everyone were suspects. The father said that he did not kill the boy, he was fixing the car outside. The mother said that she did not kill the boy, she was washing the dishes and cleaning the bathroom. The daughter said that she did not kill the boy, she was in her room all day listening to music. The maid said she did not kill the boy, she was sweeping every corner of the house. Who killed the boy?

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