Timothy Brown made his first court appearance on Thursday.
He was arrested last month and charged with abuse and neglect of an adult after his sister's mummified body was found in the trunk of his car.
According to court documents, Penny Brown was last seen alive in 2006.
30 year-old Timothy Brown is also charged with endangering the welfare of a minor. The same court documents say Timothy Brown's eight-year-old son was found living in a filthy apartment.
Brown entered not guilty pleas to each charge, and had a group of friends in courtroom as support. His long time friends say they are surprised and shocked by the charges, saying it's not the Brown they know.
His friend Beth Rutledge says he was a good caretaker, saying the reason she appeared in court was to give Brown moral support.
Brown will be back in court for a preliminary hearing next week.