New horrifying details have emerged about Maine mom Jessica Williams, who has been accused of the abuse death of her three-year-old son, Maddox Williams.

Jessica brought an injured Maddox to the hospital on June 20, but he had already stopped breathing. Jessica claimed to the emergency room staff that her son had been knocked to the ground by a dog leash and kicked by his 8-year-old sister.

However, a later autopsy discovered that the toddler's injuries were way more in numbers and severity than they initially appeared. According to a Maine State Police affidavit obtained by TV station WCSH in Portland, he had internal bleeding from a ruptured bowel, a fractured spine, bleeding on his brain, and bruises on his arms, legs and head.

Medical examiner Dr. Lisa Funte told police that temporary stick-on tattoos were placed on three partially healed abrasions on the boy's face and forehead to cover the injuries.

Jessica was arrested and charged with her son's murder on June 23. She is being held in the Waldo County jail with bond set at $150,000, reports People magazine.

She is insisting on her innocence despite the numerous pieces of evidence against her. She texted a friend "No I didn't kill my son" after her son died, and repeated the same to police on the day of her arrest.

The 35-year-old told the authorities that she "she had no idea" how her son would have acquired such injuries, except that "he bruised very easily and her kids play wild and crazy." She insisted that her son was knocked down by a leash on a puppy, and also had fallen from a trampoline days earlier but seemed fine and was not bleeding.

However, the medical examiner told the police that the boy's injuries were "too severe to be caused by kids playing, falling from a trampoline, or being knocked down by a puppy."

The police have also taken a statement from the victim's father Andrew Williams, who split up from Jessica when she was pregnant with the toddler. Andrew said that he last saw his son on April 10, and had spotted bruising on his back and a cut over an eye. He said he took photographs of the injuries "so he wouldn't get blamed" later.

Police also spoke to Jason Trefethen, the father of three of Jessica's five children, and asked him if his ex-wife was abusive towards Maddox. He replied, "You'll have to ask her."

Crime scene tape
A representational image of a crime scene. (Pixabay)