Ontario's Amber Alert system will be changed in the wake of criticism of the police response to the case of Victoria Stafford, who disappeared on April 8, 2009. (Family photo)

Changes will be unveiled this fall to Ontario's Amber Alert system because of criticism over how police handled the Victoria Stafford case, a senior provincial investigator says.

Ontario Provincial Police Commissioner Julian Fantino is behind the changes, OPP Sgt. Dave Rektor said Thursday in London.

"[The Amber Alert system] is so effective because it's not overused," Rektor said. "If it becomes misused then it weakens the effectiveness."

"It is a tool but we want to make sure it's addressing the issues," he said.

Victoria, also known as Tori, disappeared April 8, minutes after leaving her elementary school in Woodstock.

However, an Amber Alert wasn't posted immediately because police at the time said her case did not meet the guidelines for issuing one.

Before an alert is issued, police must confirm three main criteria: the child is under 18 and has been abducted, the child is in danger of serious harm, and there is enough descriptive information about the child and abductor or the suspect vehicle that a media alert would be helpful.

Stafford's remains were found in July near Mount Forest, about 95 kilometres north of Woodstock.

Two people — Terri Lynn McClintic, 19, and Michael Rafferty, 28 — have been charged with first-degree murder and kidnapping.

With files from The Canadian Press