Police arrested Timothy Brown last month after his sister's mummified remains were found in the trunk of his car.
On Thursday, new details emerged in the case during a preliminary hearing in a Scott County courtroom.
U.S. Marshals tracked Brown down in St. Louis. He was later brought back to Kentucky.
A detective with the Georgetown Police Department was the only witness at Thursday's hearing. He outlined the case from top to bottom.
They say Brown kept his 8-year-old son in an apartment so filthy, they charged Brown with endangering the welfare of a minor. It's the same apartment where investigators say Brown may have lived with his sister's corpse for years.
Court documents show Penny Brown, who was a quadriplegic, was checked out of her nursing home by her brother. He's also charged with abuse and neglect of an adult.
Police say when they found Penny Brown's body in the trunk of her brother's car, it was wrapped in garbage bags and a comforter or quilt.
No cause of death has been determined, but an autopsy shows she had been dead for several years.
Police say Tim Brown admits he could have done more to help save his sister's life.
After hearing the testimony on Thursday, the Scott County judge decided to double Brown's bond while the case heads to the grand jury.