Demand growing for cadaver dogs to assist in searches at former residential schools

WARNING: This story contains details of deaths at residential schools.

As First Nations communities in Canada continue to hone in on possible unmarked graves at the sites of former residential schools, some are now using human remains detection dogs to assist in that effort.

Since 2021, when the Tk'emlúps te Secwépemc First Nation first announced ground-penetrating radar (GPR) had identified 215 anomalies at the former Kamloops Indian Residential School, Indigenous communities across the country began conducting their own searches and are now increasingly employing multiple tools, including cadaver dogs, to do so.

GPR is limited and requires the ground to be mostly flat, said Chief Chris Skead of Wauzhushk Onigum Nation near Kenora, Ont. His community is in the middle of finalizing the number of anomalies detected near the St. Mary's Residential School where more than 6,000 students attended between 1897 and 1972.

"We knew of heavily wooded areas that we wanted to search," said Skead. "Our survivors mentioned that, so we had two rounds of cadaver dogs that came in to look and search."

Cadaver dogs contracted by ISN Maskwa, an Indigenous-led company based in Sault Ste. Marie, Ont., and working with the Wauzhushk Onigum Nation, visited areas near the grounds of the former school twice, in August 2023 and this past May.

"I think [the dogs are] a better tool," said former Ontario Provincial Police (OPP) Det. Mark Hutchinson, who's now president of Investigative Solutions Network (ISN), which owns ISN Maskwa together with the Missanabie Cree First Nation.

"Ground-penetrating radar indicates anomalies in the soil where these dogs only indicate on human remains, nothing else," said Hutchinson.

The dogs alerted handlers in 28 different locations — many of those in areas where GPR had also indicated something in the ground. Collating that information is key, Hutchinson said.

When a body decomposes, volatile organic compounds leach into the ground. Trained dogs can detect those chemicals, he said.

According to Ottawa-area dog handler and Ontario Search and Rescue Volunteer Association team manager Kim Cooper, the science around what a cadaver dog can glean from a historic grave is a little unclear.

"There is not yet science on these older graves as to what is coming off of them," said Cooper. "We know from the dogs' behaviour something is available to them, but what it is we just don't know."

CBC News recently met with Cooper and her dog Recce at an unmarked graveyard in Vars, a community in Ottawa's rural outskirts, along with two other handlers and their dogs. Each dog was taken through the area separately and given time to sniff the ground. All three stopped, sat and barked at similar locations.

"When the dogs locate odour, they will give what we call a trained final response, a TFR, which is a behaviour that they have been trained to do to let us know that they found something," said Cooper.