Smithfield, N.C. — A man accused of torturing a 4-year-old girl who later died told detectives he "lost it" and whipped the girl with a cord after she urinated and defecated in the bed they were sharing, according to search warrants released Tuesday.

Teghan Alyssa Skiba, who had had cuts, lacerations, bite marks, head trauma and sexual assault injuries, died at UNC Hospitals in Chapel Hill Monday night, according to Johnston County Sheriff Steve Bizzell.

Jonathan Douglas Richardson, 21, of 750 Old Sanders Road in Smithfield, initially claimed the girl had fallen off a bed and that he had applied an ice pack to her head. He later told a detective that he "became upset" with the girl for soiling the air mattress where they slept.

Richardson explained that he is "bipolar and little things set him off," according to the search warrant.

Authorities said Richardson took Teghan to Johnston Memorial Hospital in Smithfield at about noon Friday. Hospital workers reported the case to authorities, and the girl was taken to UNC Hospitals.

Richardson was being held without bond Tuesday in the Johnston County jail on charges of first-degree murder and felony child abuse.

Bizzell said the investigation into Teghan's death is ongoing, and others might be indicted in the case.

"The investigation is in no way over. It is ongoing," the sheriff said. "There is the possibility of others being charged. We’ll continue to work on it and go from there, but I will tell you that anybody that had a part directly or indirectly that meets the elements of a crime could be charged."

Bizzell said it's possible that the girl's mother, Helen Reyes, could face charges. Reyes, who was dating Richardson, left Teghan with him on July 6 while she left North Carolina for military training, according to the search warrant.

"In a case like this, you don't leave any stones unturned," Bizzell said.

Teghan's maternal aunt said Reyes and the rest of the family were too distraught Tuesday to speak. Teghan's father is in the Wake County jail on unrelated charges and couldn't be reached for comment.

Johnston County investigators seized an array of items from the barn where Richardson and Teghan were staying, the 2001 GMC pickup Richardson used to take the girl to the hospital and the house where Richardson's grandparents live. The barn, which is on the grandparents' property, has no running water or bathroom.

Items seized included an air mattress, a condom wrapper, a shotgun, a rifle, ammunition, knives, a camera, duct tape pieces, a green, leafy substance, drug paraphernalia, guitar string and a drop cord, according to a warrant.