EASTON, Pa. -

Investigators are looking into the deaths of three other children of a couple going to trial for allegedly letting their daughter's teeth badly rot.

Jessica Hoffman and Ken Wanamaker are facing charges for allegedly allowing their six-year-old daughter's teeth to rot so badly that a dentist said it could have been deadly.

"I was informed that we had a family here that had this child that seemed to be getting inadequate care, that we had a death of a child that occurred, I think it was in 2007, 2011, 2013. Obviously, it raised a red flag in my mind that we ought to make sure that we go back and look at all these matters," said Northampton County District Attorney John Morganelli.

"We just want to make sure that nothing was overlooked. This is not to suggest or imply that there was some crimes that might be prosecuted from these prior incidents," he added.

Lehigh County Coroner Scott Grim said Tyson Wanamaker was about seven-months-old when he died. It was ruled a natural death due to chronic pneumonia.

Grim said Hoffman has also had two stillbirths.

Colton Wanamaker died of natural causes due to extreme prematurity at 22 weeks; Krystopher Wanamaker was stillborn at 34 weeks. That death was attributed to intrauterine fetal demise associated with maternal meth use, according to Grim.

"In Pennsylvania, we have a statute on the books that specifically exempts a mother from criminal liability when it comes to any type of conduct that brings harm to her unborn child," Morganelli said.

Morganelli said he may have an update as early as next week.