A 41-year-old Black Diamond man who authorities say neglected his elderly mother while she was under his care was charged Monday with first-degree manslaughter.

Christopher Wise has pleaded not guilty to the charge.

King County sheriff’s investigators say that when they found the body of Ruby Wise in a Black Diamond home on June 16 after her son called police to report her death.

Ruby Wise, 88, was so emaciated and her bed sores so deep, that deputies could see her left shoulder blade through an abscess, according to charging papers. The woman’s 70-pound body, dressed only in a hospital robe and soiled adult diaper, lay in a bed stained with blood, urine, feces and pus. Flies had begun to gather around her lips, according to charging papers.

The King County Medical Examiner’s Office attributed Ruby Wise’s cause of death to complications with the eight large extremely deep bed sores on her body.

Christopher Wise he said that he was his mother’s sole caregiver for the past 10 years, according to charging papers. Wise said that it had been about two years since his mother had seen a doctor, court documents said.

He told investigators that he had been feeding his mother every two hours — mostly giving her a half of a banana, a small Snickers bar and bread soaked in juice, charging papers said.

Deputies found earplugs in the living room of the home, which Wise said he would use to drown his mother’s moans, court papers said.

Wise’s next-door neighbors told investigators that they heard the woman moaning and yelling for help since April.