U.S. and New Zealand law enforcement action against filesharing kingpin Kim Dotcom and associates was set in motion over a year ahead of the raid on the Megaupload founder’s mansion in January, and police knew their tactical assault by helicopter would be perceived as overbearing, redacted police documents show.

Known as the “Blue Folder,” the planning documents obtained by Computerworld from the Auckland High Court reveal that that N.Z. Police enlisted the assistance of the SWAT-style Special Tactics Group (STG) and Armed Offenders Squad (AOS) for an armed, helicopter-borne assault on the Dotcom mansion at 0700 hours on Jan. 20 this year, New Zealand time.

The documents shed more light on the U.S.’s determined prosecution of Dotcom and fellow executives, which involves felony charges of racketeering, a complete shutdown of one of the net’s most popular file-sharing sites and legal theories that could just as easily been wielded against YouTube. Dotcom remains free in New Zealand, pending an extradition hearing scheduled in the spring of 2013.