INDIANAPOLIS -- An autopsy conducted on Saturday indicated a 4-year-old Indianapolis boy died from a fractured skull.

Elijah Simpson, 4, was brought to Community East Hospital by his mother, Courtney Simpson, (pictured, right) Friday after she found him unresponsive, police said.

Investigators said Elijah, who was already dead when he arrived at the hospital, had been hogtied and beaten by Courtney's boyfriend, Christopher Montgomery (pictured, left).

Police said the Courtney Simpson told them that the boy was being disciplined for sucking his thumb.

Simpson originally told police that the boy's 5-year-old brother tied him with a shoelace at a motel room in the 2300 block of N. Post Road, but recanted after further questioning Saturday.

Simpson told police that Montgomery struck Elijah Simpson in the head and then used a drawstring of a hooded sweatshirt to restrain him.

"He (Montgomery) threatened her -- told her that if she went to the hospital, he was going to kill her and the kids before the police got there," said Lawrence Simpson, the boy's grandfather. "He (Elijah) was just a little light. He was a child. I miss him right now. Everything's going to work out."

Montgomery, who was being held in connection with unrelated robbery warrants, was charged with murder. Simpson faces charges of neglect of a dependent.

The 5-year-old boy was taken into protective custody.