By Owen Gleiberman
Updated August 11, 2010 at 04:00 AM EDT

Alan G. Parker’s documentary Who Killed Nancy? takes a scary, fascinating deep dive into the punk-rock abyss of former Sex Pistol Sid Vicious and his American groupie girlfriend, Nancy Spungen. Their solipsistic heroin-den love affair is a hell-bent comedy of mishap (Alex Cox’s Sid & Nancy caught it quite accurately), but the laughs get stuck in your throat when you hear an eyewitness account of how Sid strangled a cat. The question the film comes around to is, Did he also kill Nancy? That’s what the police decided after she died of a single stab wound on Oct. 12, 1978, at NYC’s Chelsea Hotel. But the film offers evidence that Vicious spent the entire night out cold on barbiturates. It plants resonant doubts. B+

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