The North York teenager's body was found on the 16th Sideroad in King Township on Nov. 30, 1972. Sunday marks the 42nd anniversary of that grim discovery.
Leroux was just 16 years old at the time of her death. Police would later reveal that she had died of blunt-force trauma.
York Regional Police Det-Sgt. Jim Killby said it's hard to imagine what Leroux’s family has gone through over the years, as the pain has never gone away for her surviving parents and three siblings.
"We are in contact with the family on a regular basis and like all of these cases, we feel their pain when these anniversary dates approach," he said.
Killby said that police have a male DNA profile from the crime scene, which remains unidentified.
A $50,000 reward is available, in a bid to generate tips that can help police close the case.
Killby said he is "100 per cent confident" that there is someone out there with the information police need.