On the one-year anniversary of the original slayings, the OPP believe they have solved the mystery of four murders last summer in Kirkland Lake, Ont.

“Investigators have linked two double homicides in Kirkland Lake to one suspect,” the OPP said Tuesday afternoon in a news release.

This was a break in the case that grieving families in the northern Ontario community have been hoping for. But it turns out the accused killer is dead, too.

Martyn Rosko is pictured in a photo posted to Facebook.
Martyn Rosko.

OPP investigators have linked the four homicides to one suspect, Martyn “Marty” Rosko, 38 years old of Kirkland Lake,” said the release. “The suspect has since died and cannot be charged criminally. Had the suspect been alive, compelling grounds exist to charge and prosecute him with murder charges for the four victims.” 

Amanda Lachapelle, 37, and Gabriel Marercki, 49, were found slain in Kirkland Lake on July 30, 2023.
Amanda Lachapelle, 37, and Gabriel Marecki, 49, were found slain in Kirkland Lake on July 30, 2023.Timiskaming Funeral Cooperative

Needless to say, this was a tough pill to swallow for the families of Gabriel Marecki, 47, and Amanda Lachapelle, 37, who were found dead in a residence on Woods St. in Kirkland Lake on July 30, 2023, at 4:30 p.m. Lea Thompson, 33, and Kyle Robertson, 37, were then found slain in a home on Kirkpatrick St. on Aug. 8, 2023, just before 8 p.m. 

Two double murders a week apart. 

Kirkland Lake residents Amanda Lachapelle, 37, and Gabriel Marecki, 49 (seen here), were found dead in a residence on Woods St. on July 30, 2023.
Kirkland Lake resident Gabriel Marecki, 49, was found dead in a residence on Woods St. on July 30, 2023.Facebook

While Rosko was arrested and detained on another matter — he was charged with two counts of arson/disregard for human life and three counts of failing to comply with a probation order after being arrested on Aug. 7, 2023 — police went to work to try to piece together this strange puzzle, first to determine how these four individuals died, by what means and for what reason? 

A lot of the questions remain unanswered. 

“I still have no idea,” Thompson’s mother Tammy said on Tuesday. “We still don’t know officially what happened.” 

But she would like to know and is calling for Ontario’s chief coroner to ask for an inquest into the case. 

“Since there will be no trial, having an inquest will help us understand it,” said Tammy. 

Lea Thompson
Lea Thompson, 33, of Kirkland Lake, Ont., has been identified by OPP as one of two people found dead in a Kirkland Lake home on Aug. 8, 2023, after a wellness check.Photo by Tammy Thompson /Facebook

She said she believes the motive for her daughter and friend’s death could be related to information they may have had on the other slaying. 

“I believe Lea was going to tell police what she knew,” said Tammy, who confirmed her daughter and Rosko had been dating.

Marecki’s sister Nathaly told the Toronto Sun that it has been a long year waiting for herself and her brother’s two young children, who are nine and 12 years old and now in Nathaly’s custody. 

“I am raising them now,” she said. 

While they live in Quebec, “we will come back here every year to place flowers in memory of my brother.” 

Tammy is raising Thompson’s 10-year-old daughter, who she said is coping in light of her mother’s slaying. 

Both said it has been an extremely “long” year waiting for this day – something investigators made clear they understood. 

“The OPP recognizes that there has been public interest into these tragic incidents that not only impacted several families, but the entire Kirkland Lake community,” police said. “We thank the public and media for their patience as we conduct thorough investigations into these deaths.” 

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And this case is far from over as the police said anyone with information can contact the OPP at 1-888-310-1122 or Crime Stoppers anonymously at 1-800-222-TIPS (8477) or ontariocrimestoppers.ca. 

The biggest enigma in this case is Rosko himself. What was behind these allegations and what has been described to family members as a suicide in a North Bay jail? 

“Obviously somebody who does something like that has some serious issues,” said Nathaly. 

Tammy said anything that can be learned from this case and what caused it is important to pursue. She is in touch with Rosko’s family regularly and said they are also shocked and saddened by this bizarre turn of events. 

After a year, families now know who police suspect is responsible for these heinous crimes, but Tammy and Nathaly said there is no closure. 

“Nothing is going to bring them back,” said Nathaly.