Murder charges were dropped against an Ontario woman Thursday who had insisted that a pit bull killed her seven-year-old daughter.

"I have maintained my innocence for almost four years, and I'm thankful that today they've realized that I didn't do this," said Louise Reynolds.

The woman was charged with second-degree murder after the body of Sharon Reynolds was found under the basement stairs of her house on June 12, 1997.

Initially a pathologist said the child bled to death from what appeared to be stab wounds to her head.

Reynolds spent two years behind bars and two years in a halfway house waiting for the trial.

But some evidence was lost, and her daughter's body was exhumed for a second autopsy. A different pathologist concluded that many of the 80 cuts were probably caused by a pit bull.

On Thursday prosecutor Bruce Griffith said authorities were no longer certain how the girl was killed.

"After a very careful review of the state of the evidence presently available we are of the view that the Crown no longer has proof that this death was caused by stab wounds," he said.

Reynolds expressed relief after being freed.

"I'm glad it's over, and I just want to thank everyone who has stood by (me) through this," she said. "I just want to go home."

But not everyone is convinced justice was done.

"I can't believe this is the best we can do for a seven-year-old girl," said a police officer who led the investigation. "This should be going ahead to trial, to a jury."

The dead girl's grandmother, Kathy Haubrich, began screaming inside the courtroom when the murder charge was withdrawn.

"You're guilty," Haubrich told Reynolds. "You will rot in hell. You left her to die."