New court documents released details of the investigation into the death of a 5-year-old boy in Newport News, Virginia, in which case the child's mother and her partner remain detained and face charges of second-degree murder and child abuse.

Previously, Newport News Police had arrested Katrina Sudberry, 27, the child's mother, who faces charges of second-degree murder and serious child abuse.

An autopsy determined that the child died from blunt force trauma.

The investigation began on July 16, when officers responded to a home located on Walden Pond Court after receiving a report of an unconscious 5-year-old child.

Paramedics tried to revive him and took him to a nearby hospital, where he died hours later.

According to Newport News Police, an autopsy conducted by the Medical Examiner's Office concluded that the child died from internal injuries caused by blunt force trauma.

Investigators also noted that the child had injuries to the liver, stomach and intestines, as well as injuries classified as “catastrophic” in different parts of the body.

The mother admitted to physically punishing the minor

According to the criminal complaint, Sudberry told investigators that he had disciplined his son in the days before his death using his hands and a belt.

He also admitted to forcing the boy to perform physical exercises such as push-ups and squats against the wall as a form of punishment.

The woman, who authorities say is pregnant with Martin's child, stated that the morning the death occurred she left the child alone with her partner for approximately 45 minutes.

Upon returning, he observed that the belt used by both to punish the minor had a broken buckle, although he assured that it was intact before leaving the house.

According to court documents, Sudberry acknowledged that he did not immediately call emergency services because he “knew what” the situation would look like.

Text messages show conversations about punishments

The investigation also included text messages exchanged between the couple, obtained by authorities.

According to those documents, Sudberry sent a message to Martin indicating that the child had more bruises while they were still trying to make the previous ones disappear.

Martin reportedly responded by asking if she would allow him to continue punishing the minor.

Later, after the mother sent him photos of the boy's injuries, Martin allegedly wrote that he would stop hitting him and limit punishments to physical exercises.

Both will remain detained until their next hearing.

Both Sudberry and Martin remain held in the Newport News jail while the court process continues.

According to authorities, both are scheduled to appear in court again on September 9.

At this time, the investigation remains ongoing and authorities have not said whether they will file additional charges.