As the DPRK had already clarified, it has nothing to do with the case. The DPRK has always abided by international law but the U.S. made such absurd assertion which reminds one of a thief crying "Stop the thief!"
The fabrication of the case and the "results of the investigation into it" are, in the final analysis, nothing but a farce orchestrated by the group of traitors with the approval of the U.S. and under its patronage.
The U.S. claimed that there was hardly any side which was ready to do so except north Korea and that the cause of the sinking of the warship was most likely a torpedo attack by north Korea even before the announcement of the results of the investigation, paying lip-service to scientific and objective investigation. From the very day the case occurred, the U.S. branded the DPRK as a "suspect" and led the investigation into the case in that direction.