A Wisconsin couple was arrested after the woman’s two sons reportedly escaped their home last week covered in blood and feces.

On July 13, a Milwaukee resident saw Katie Koch’s two sons, ages 7 and 9, climb onto an air conditioner unit and walk down the street naked. A child who witnessed the ordeal described the boys as “cavemen [who acted] like they had never seen the sun before,” according to WDJT.

Residents also reported that the boys were covered with blood and feces. Prosecutors said that responding police officers located Koch — who was asking a man on the phone if he was “almost home, so you can help explain what’s going on,” WITI reported.

An investigation revealed that Koch, 34, and her boyfriend, Joel Manke, 38, were living in a filthy home that reeked of feces and urine. The Milwaukee Journal Sentinel reported that feces was smeared on the boys’ walls and that they had to get their heads shaved because their hair was matted with feces.

According to the Daily Beast, Koch and Manke kept the boys in a bedroom with boarded-up windows for years. They are allegedly not potty trained, cannot read or write, and one of them is unable to use full sentences.

Prosecutors also alleged that Koch admitted to never enrolling her sons in school. Her boyfriend told cops that he never confronted Koch about her parenting to avoid arguments, according to the Journal Sentinel.

Koch is charged with chronic neglect of a child, false imprisonment, and neglecting a child. Manke is charged with chronic neglect of a child and false imprisonment.

Koch allegedly penned a three-page apology letter to her sons. Its contents were not disclosed.

Subscribe to the ‘Crime Stories with Nancy Grace’ podcast. Listen to the latest episode:

[Featured image: Milwaukee Police Department]