A Detroit-area doctor sexually assaulted and critically injured a 13-month-old girl while babysitting for her, a prosecutor says. David Montaldi, 31, of Mount Clemens was arraigned Monday in Clinton Township District Court on first-degree criminal sexual conduct and child abuse charges. Judge Linda Davis ordered him held without bond in the Macomb County jail. It was unknown if he has a lawyer. The charges carry a possible sentence of up to life in prison. The girl had three or four skull fractures and other injuries, Macomb County Sheriff Mark Hackel said at a news conference Monday. “The child is in very critical condition,” Hackel said. The girl was being treated at Children’s Hospital in Detroit. Montaldi was watching the girl while her mother worked Sunday and called the woman to say a dog may have hurt the toddler, Hackel said. The sheriff said that story appears to be untrue. Montaldi was a medical resident at Mount Clemens Regional Medical Center under an ear, nose and throat specialist for about two months ending Oct. 28, hospital Vice President Sharyl Smith told the Detroit Free Press. “We have no reason to believe that any patient care was compromised,” Smith said. She said the hospital informed its staff of the charges and was offering help to any of them who need it.