Smithfield, N.C. — A man accused of torturing a 4-year-old girl left in his care could face more charges, Johnston County authorities said Monday.

Sheriff's deputies arrested Jonathan Douglas Richardson, 21, of Old Sanders Road, Friday on a charge of felony child abuse after he took the girl to a local hospital and claimed she had fallen off a bed.

Hospital workers contacted law enforcement authorities, Sheriff Steve Bizzell said, after finding the child had cuts, lacerations, bite marks and signs of sexual assault.

Sheriff's office spokeswoman Tammy Amaon said Monday that authorities are still investigating and that further charges haven't been ruled out.

The girl, who also suffered severe head trauma, was in critical condition Monday at UNC Hospitals in Chapel Hill.

Meanwhile, Richardson made a first court appearance on the felony child abuse charge. A Johnston County judge left his bond at $1 million and ordered that he be appointed a public defender.

Authorities haven't said how long the child was in Richardson's care, but arrest warrants indicate the dates of the offense from July 14 to July 16.

Bizzell said the girl's mother had been away for military training but has since returned to be with her daughter.

"(This is) one of the worst cases of torture of a child that we have ever investigated," Bizzell said in an interview Saturday.

"I have detectives out here, professional law enforcement officers, who are saddened by this. It is just unreal," he added. "We can not imagine someone who would do this to such a young child."