The teenage serial murder suspects sought in a weeks-long manhunt across Canada recorded their last will and testament on a cellphone before fatally shooting themselves, relatives said in a new report.

A video message filmed by Bryer Schmegelsky, 18, and Kam McLeod, 19, could hold the key to why they embarked on a killing spree in British Columbia this summer, allegedly killing a local professor and an American woman and her Australian boyfriend.

About 30 seconds of the footage was shared with family members of the former fugitives, The Toronto Star reported Monday.

In the clip, the teens said goodbye to their families and described their wishes for their remains, a family member told the Star.

The Royal Canadian Mounted Police (RCMP) have the full recording, the relative said. A police spokeswoman wouldn’t confirm the existence of the video.

Authorities found the ex-fugitives, dead of self-inflicted gunshot wounds, Aug. 7 in dense brush near the shoreline of the Nelson River in Gillam.

Weeks before taking off on what their parents believed was a road trip to Yukon, the Vancouver Island teens were working at a Walmart.

They were initially feared missing when their burned-out truck was found July 22 on the side of a remote highway.

Authorities then charged them with second-degree murder in the death of Leonard Dyck, 64, a University of British Columbia professor whose body was found about a mile from their truck.

The teens were also suspects in the deaths of Charlotte, North Carolina, woman Chynna Deese, 24, and her boyfriend, Lucas Fowler, 23, of Sydney, Australia, who were found fatally shot July 15, along the same highway.

A manhunt for the pair stretched across three rural Canadian provinces, ending earlier this month when their bodies were found, along with two firearms.