The first trailer for the documentary The Imposter has gone online. The film premiered at this year’s Sundance Film Festival to rave reviews, with our own Matt Goldberg calling it “one of the best thrillers in years.” While that statement seems odd given that The Imposter is a documentary, one look at this trailer and you’ll understand. The pic tells the story of a family whose son went missing from San Antonio, Texas, only to apparently turn up three years later in Spain. Director Bart Layton makes heavy use of reenactments and dramatizations that look to be pulled off quite well; this isn’t your cheesy Bio channel special. I’ve heard that the less you know about this movie the better, and this trailer acts as a wonderful teaser without really giving much away.Hit the jump to watch the trailer. The film was recently acquired by Indomina Group for distribution and will receive a theatrical release later this year. The Imposter will also screen at this year’s SXSW Film Festival next month. [Update: We've been asked to take the trailer down as it's not the official theatrical trailer after all. We'll bring you the official trailer once it's released]