The CSOP Headquarter is a big skyscraper near Washington DC. It's outlying out of Washington. It's mostly used by the CSOP for secret meeting. After Kira learned that there was a secret society called CSOP who wanted to kill him. Both J and Sebastian Tabler learned from the secret society at the same time. Both of them, got the secret army of the CSOP under their control. The army of fifty men was split, and twenty-five soldiers fought again other twenty-five soldiers. After the massacre was done, and none of the army had won so far, another group of soldiers wanted to get the skyscraper under their control.
J saw no other choice in destroying the CSPO by hacking the database, get the name of every other society who existed. After he did that, he and Sebastian both blew up the skyscraper at the same time.