"I immediately said a prayer that she would die," said Dr. Richard Barbaro.
Barbaro went on to say the case is the worst thing he's seen in his 30 career in forensic odontology, and that he has never seen so many bite marks on a person.
Richardson - the former boyfriend of Skiba's mother Helen Roxanne Reyes - was supposed to be caring for the child over a 10-day period while Reyes was out of state for Army Reserves training in July 2010.
Prosecutors say Skiba was tortured, sexually assaulted, and beaten inside an air conditioned shed behind Richardson's grandparents' home, where she was living. There was no running water, no bathroom, and just a single air mattress on the floor to sleep on.
Richardson took Skiba to Johnston Medical Center claiming she had fallen off the bed. However, doctors found she had cuts, bruises, a head wound, and bite marks on her body. Skiba died days later from her injuries.
Richardson is charged with first-degree murder and felony child abuse inflicting serious bodily injury. Prosecutors are seeking the death penalty.
Richardson's defense attorneys have argued that client is mentally ill and that the Johnston County girl's death was a tragic accident.
On the witness stand Monday, Dr. Barbaro told jurors that the bite marks on Skiba's body were an exact match for Richardson. He said some were so extreme that the flesh was literally torn off.
He said there were more than 60 marks that covered her all over.
"Bite mark injuries would inflict a lot of pain," said Barbaro. "The pain of tearing off skin would be excruciating."