When the family of Barry and Honey Sherman decided to conduct their own investigation into the couple’s deaths, they joined a list of other families who have made the same decision after a loved one died in unexplained circumstances.

The pharmaceuticals mogul and his wife were found dead in their North York home last Friday. Toronto police later confirmed that the Shermans died of “ligature neck compression,” and classified the deaths as suspicious.

Toronto police spokesperson Mark Pugash told the Star Thursday that the service would not be commenting on the Sherman family’s plan to conduct a separate investigation.

“They’ve done the only thing they could have done,” said Joanne MacIsaac, the sister of Michael MacIsaac, a 47-year-old man who was shot dead in Ajax by a Durham police officer in December 2013. The MacIsaac family believes he was in crisis after suffering an epileptic seizure.