On the early morning of Feb. 17, 1970, one of two sequences unfolded at 544 Castle Drive, the Fort Bragg residence of Army surgeon Jeffrey R. MacDonald. In the first scenario, drug-addled hippies burst into the house, chanting, “Acid is groovy,” and, “Kill the pigs,” before stabbing to death MacDonald’s wife, Colette, and daughters, Kimberly and Kristen. In the second, the doctor himself committed the crimes and invented the Charles Manson-inspired fantasy to cast suspicion elsewhere. Though A Wilderness of Error, FX’s new investigative series based on the book by documentarian Errol Morris (The Fog of War), isn’t sure which story to believe, its examination of the famous case is necessary viewing for true-crime enthusiasts.

Unlike Making a Murderer, the 2015 Netflix megahit that reinvigorated the genre, A Wilderness of Error makes no effort to hide its subject’s fate. Cleared of wrongdoing by a military tribunal, MacDonald was nevertheless indicted by a North Carolina grand jury in 1975. There, despite the confidence of his defense team, the doctor was convicted of three counts of murder and ordered to serve consecutive life sentences in prison. By revealing the trial’s outcome in the opening credits, director Marc Smerling (The Jinx, Capturing the Friedmans) sacrifices the element of suspense but gains the more interesting proposition that an injustice may have been done.