According to his narration in “No Stone Unturned,” the director Alex Gibney stumbled upon the subject matter of this film while working on another documentary about the World Cup. On the evening of June 18, 1994, in a pub in a small village in Northern Ireland, a group of men were watching a World Cup game taking place an ocean away. Two balaclava-wearing men came into the establishment and killed six people.
In this film, Claire Rogan, the widow of one of the victims, recalls being told by the authorities that there would be “no stone unturned” in bringing the killers to justice. “I don’t think they ever lifted a stone, never mind turned it,” she says.
The killings are still, over two decades later, officially unsolved, though the militant Protestant Ulster Volunteer Force claimed responsibility for the attack. Mr. Gibney’s film reveals significant aspects of the case, many of which were hidden in plain sight and shed light on corrupt practices. The film also shows reasons the case was not pursued aggressively. The Irish Republican Army declared a cease-fire in August 1994, a significant step in putting an end to “the troubles” of Northern Ireland; in some circles, it was thought that an investigation at that time would stir things up too much.
What Mr. Gibney uncovers is grave and shocking and could make a viewer concerned for the safety of the filmmaker. But its presentation is flawed. The movie contains ill-advised simulated scenes that recreate the crime and other stylistic touches that struck me as window-dressing.
Correction: November 10, 2017
An earlier version of this review misstated the setting of the documentary. It is Northern Ireland, not “Northern Island.”