LAST June the first season of “The Killing” on AMC ended without a bang. A gun was pointed at a murder suspect’s head, and then there was a quick cut to the credits. The explosion came later, when complaints poured in that the show had failed to solve the season-long mystery the network had advertised with the teasing slogan “Who Killed Rosie Larsen?”

In the wake of that cascade of ill will I had two thoughts. One was that if the show’s writers had wrapped up the story in that 13th episode, those same fans and critics would have complained — justifiably — that the season had been rushed and confusing and that the killer had been identified too abruptly.

The second was that if you really wanted to know the answer, or an answer, all you had to do was watch “Forbrydelsen,” the Danish show on which “The Killing” was based. It revealed who killed Nanna Birk Larsen, Rosie’s European antecedent, way back in 2007.

That’s what I did recently in preparation for Season 2 of the American show, which begins Sunday night on AMC. You can do it too, and legally, even though “Forbrydelsen” (“The Crime”) hasn’t been distributed in any format in America. A nicely packaged DVD set of the first season, with English subtitles, can be ordered online — it currently costs about $38 plus shipping from Amazon’s British site — and watched on a computer with a media player that ignores regional coding.