Doctors and lawyers question the validity of Shaken Baby Syndrome. Experts worldwide, from England to Japan, are taking a second look at cases that put people in prision for shaking a baby. Some medical professionals and lawyers say there's just not enough known about Shaken Baby Syndrome to make convictions.

A Macon woman spent four years of her life surrounded by the fear of something she says she didn't do.

"At first I was just terrified. Completely terrified," Kathy Hyatt said.

Everything changed for Kathy Hyatt four years ago.

"I would just sit on my couch and look out the window and think the police were going to come get me," Hyatt said.

Prosecutors accused her of shaking a baby in her care. From day one Hyatt denied it.

"I would never hurt that baby. I loved her. I mean, I took care of her from the time she was little bitty, just barely born up until that time. I mean, she was like my own child. She took her first steps in this room," she said.

There was only one thing Hyatt could do.

"I just started researching on the Internet and tried to find out what this whole world of Shaken Baby Syndrome was about," Hyatt said. 

Hyatt found a world full of controversy. She and her husband have stacks and stacks of articles that question the science behind it.

"The red blotches are blood that normally should not be there," MU Mason Eye Institute opthalmology professor Dr. Joseph Giangiacomo said as he showed a digital picture of an eye with retnal hemorrhaging.

Prosecutors across the country use him as an expert witness. He says there are two key signs doctors look for: retnal hemorrhaging and cerebral hemorrhaging, or bleeding in the eye and in the brain.

Are these two signs enough for diagnosis?

"It takes, you know, the history - the history as far as giving a reproducible, consistent response. Who is watching the child? What's the environment like? Could you explain this from a fall in a high chair? No," Giangiacomo said.

"The amount of force that it takes from just shaking a child to cause a cerebral hematoma hemmorghaing is so significant that if a person just shook a child without impact to the head that the amount of force required would actually end up decapitating the child before you'd see those signs or injuring the neck first," Hyatt's attorney Kirk Zwink said.

"It has to take some type of momentum where the head is unsupported and it's wallowing...boom and boom. And this is an acceleration, deceleration, and you're doing this whooping back and forth," Giangiacomo said as he motioned with his hands.

Hyatt's lawyers ask doctors for one thing: research.

"They take it as a matter of faith and what's disturbing to me is that once they get it in their head, you can't shake that. There's no science behind it. I wouldn't even call it a theory, Shaken Baby Syndrome, I would call it a hypothesis," Zwink said.

"But if you're looking for an experimental model to prove or disprove this, it's very hard," Giangiacomo said.

A split in the science world that Kathy Hyatt still investigates. She was found not guilty in January. She belongs to support groups and forwards information she's found to people across the world going through what she went through. She had many character witnesses for her trial.

"She had over 200 character witnesses that we had endorsed to possibly use in the trial, and, you know, there again with that history there would be somebody that would at some point have seen something that would indicate that she could lose her cool with a child, but there wasn't anything like that," Hyatt's attorney Rick Tucker said.

Hyatt said her friends and family always supported her.

The baby in Hyatt's case is five years old and still lives in the Macon area.

Audrey Edmunds was accused of shaking seven month old Natalie Beard on October 16, 1995. In 1996, Edmunds was sentenced to 18 years in prison. She always maintained her innocence. The expert witnesses in her case later said the child's symptoms could be linked to other causes. The Wisconsin District IV Court of Appeals granted Edmunds a new trial in March 2007, after she'd been incarcerated for ten years. Edmunds walked free in February of 2008 after a decade behind bars. She's now in her forties and has three grown daugthers.