"We had nothing else to go on," Lee-Anne Cartier tells the BBC. Her brother, Phil Nisbet, was found dead in his truck in May 2009, and police pegged it as a suicide. A toxicology report revealed high levels of an antihistamine he was knowingly allergic to, and Cartier reluctantly agreed the death must have been intentional, even though she couldn't comprehend what would have driven him to end his life. It turns out the intentional part was right, but not the rest. The BBC tracks the unraveling of the case, which began when Nisbet's second wife, Helen, read Cartier a suicide note she said she'd found that declared his youngest son, Ben, whom he'd had with his first wife, wasn't his. Helen also claimed a DNA sample had been taken at the funeral home and proved that assertion—which Cartier now explains would mean Ben wouldn't have a claim to her brother's life insurance money.
But it wasn't until she flew from Australia to New Zealand and visited Helen that the truth became clear: Helen offered up the suicide note, which was typed and bore a signature that wasn't her brother's. "So I just started sculling my drink and going to myself, 'Oh my God, she's killed him.'" And then her detective work began: She spoke with the funeral director and debunked the DNA sample story; she arranged a DNA test for Ben that killed that assertion, too. And she spoke to Helen's co-workers, who allegedly said she'd made comments about rat poison and her husband that were so extreme they jokingly called her the "black widow." But even with all Cartier's evidence, police wouldn't reopen the case. So she requested an inquest at the coroner's office in November 2010. Three years later, Helen stood trial—and was found guilty on two of three counts. Read the full story for more on the trial and outcome. (Read more Longform stories.)