Three Wisconsin brothers repeatedly assaulted younger sister for years, according to police, and the children’s father reportedly shrugged it off and did nothing to intervene.

TMJ 4 reports that three brothers, identified in a criminal complaint as James Keene, 29, Elijah Keene, 27, and Josiah Keene, 20, are facing several “sexual assault of a child” charges. The brothers’ father, Brian Keene, 62, faces neglect and failure to act on sexual abuse of a child charges.

According to the criminal complaint, Elijah Keene admitted to police he “was addicted” and sexually assaulted his three younger sisters in their South Milwaukee home for around six years. The victims are now between the ages of 10 to 19.

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Brian Keene allegedly admitted that he knew something was going on, but shrugged it off to his sons having “raging hormones.” He then asked the officer if he sons were being arrested, and said he relied on them for income.

Police were alerted to the abuse on April 8, when someone sent a tip regarding a suspicious vehicle at the home. According to Fox 6, an officer arrived and spoke with a female, 19, who claimed the home was “unsafe.” Afterward, the officer went inside to take statements from the children in the home.

Upon walking into the home, the officer noticed a filthy mess throughout the residence. The children’s clothing had a bad smell, as if they hadn’t bathed or washed their clothes in quite some time.

The children told the officer that the “house was very dirty, they were not going to school, there were holes in the walls and floors and they used space heaters because there was no heat,” the complaint read.

The officer took the children to the police station for official statements, where authorities learned about the sexual abuse.

The victims told police that all three brothers brought them to the basement on multiple occasions. The brothers forced the girls to perform sexual acts on them, the complaint read.

On April 9, the officer took the kids back to the home to collect their clothes and other belongings. During the second trip, the officer “observed that there were nails sticking up in the kitchen floor to the point that he actually tripped on one of these nails.”

The officer then spoke to Brian Keene, who allegedly admitted he hadn’t made his children go to school in five years, after his wife left them. Further, he said he hadn’t taken them to a doctor in over a decade, but asserted that “none of them were ever sick.”

All four suspects are currently behind bars. Their next scheduled court date is April 23, for a preliminary hearing.

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[Featured image: Joy Monell/Facebook; Jessica Monell/Escambia County jail]

*Editor’s Note: Story updated to reflect the incident occurred in Wisconsin. A previous report indicated the suspects lived in South Dakota.*