Left to right: Kaitlin Evans, Kirby Rankin, and Nessa Keaney (Hamilton County Sheriff's Office).

A 38-year-old mother in Ohio and two other women are accused of severely abusing and ultimately killing a 7-year-old boy, whose body was found "bound with duct tape" inside a closet in the home where the women lived.

Kaitlin Evans, Nessa Keaney, and Kirby Rankin are each charged with murder and child endangerment in connection with the death of William Evans, court records show.

The allegations described in court Friday were so disturbing that a veteran homicide detective called the case "the most disturbing example" of child abuse he had encountered during nearly three decades in law enforcement, local Fox affiliate WXIX reported.

Evans, the boy's biological mother, lived in the home with Keaney and Rankin, and all three women were described in court as being responsible for co-parenting William, according to local NBC affiliate WLWT. Court records state the boy was "mentally handicapped," though authorities did not disclose his specific condition.

Officers with the Cincinnati and Norwood Police Departments responded to a home in the 2800 block of Madison Road shortly after 1 p.m. on Aug. 6 regarding a report of a possible disturbance, according to a report from The Cincinnati Enquirer. First responders found William inside the home, where emergency medical personnel pronounced him dead.

At Friday's arraignment, Hamilton County Assistant Prosecutor Kate Burroughs reportedly told the court that William's body was located inside a closet with his hands and feet bound with duct tape. The prosecutor said there was evidence showing the boy had been subjected to at least two months of physical and mental abuse at the hands of his mother and her two housemates.

A detective testified that William had injuries consistent with repeated physical beatings, including impact injuries to the back of his head, local CBS affiliate WCPO reported. He said the boy suffered "a number of injuries that would indicate physical beatings, blunt force injuries from a striking device on the face, torso, back, upper and lower extremities."

The detective reportedly told the court that William was subjected to what he described as "water torture," saying, "We believe the victim was choked underwater — held underwater for a long period of time."

He added that there was "also some burn torture involved."

None of the women in the house sought medical help or contacted police despite all having witnessed the alleged abuse, prosecutors reportedly said.

The defense attorneys, however, disputed the extent of their clients' alleged involvement in the boy's death.

Evans' attorney, Brandon Fox, characterized the allegations against his client as a "failure to act" rather than active violence, per WXIX. Fox sought sympathy for his client, saying "she just lost her child."

Keaney's attorney likewise reportedly argued that his client was "the least culpable" of the three women, claiming she had even attempted to treat some of William's injuries.

Highlighting the women's failure to seek medical assistance for William, prosecutors said all three women left William home alone to take one of their pets to a veterinarian for a checkup just one day before the boy died.

However, a detective testified that Rankin disclosed her own involvement in what investigators described as a "prolonged child abuse incident" and implicated Evans and Keaney as "active participants" in the abuse.

Rankin's attorney requested a competency evaluation, citing "documented serious mental health issues." The judge agreed to the request and set a hearing date for Sept. 4.

Authorities are awaiting the completion of an autopsy before releasing an official cause of death. Prosecutors said additional charges are expected following the results of the procedure and additional interviews are completed.

William's other biological parent attended Friday's hearing and was permitted to address Evans. The parent, who was not identified by WXIX, said, "William was my life, and I trusted you to care for him."

The parent also told the court that the defendants had kept William away for nine months "over lies."

A judge set bond at $1.1 million for each defendant — $1 million for the murder charge and $100,000 for child endangerment, records show.

A Hamilton County grand jury is scheduled to hear the case Aug. 17. All three women have pleaded not guilty.