On Saturday night, Abu Bakr al-Baghdadi chose suicide over death or capture at the hands of the Delta operators of A Squadron. The operation, however, had begun months before the Delta shooters came in knocking at the leader of ISIS’ door.

The story behind the tracking of the leader of the Islamic State (ISIS) is as intriguing as the details of the Delta Force raid.

According to emerging reports, U.S. intelligence was able to pinpoint the location of the terrorist leader with the help of an informant, who was in al-Baghdadi’s close circle. The unnamed informant was an ISIS member and responsible for organizing and facilitating al-Baghdadi’s movement within Syria. He was also responsible for the construction of the compound where the terrorist leader was hiding. This knowledge would be key in the planning of the operation, since the Delta operators and Rangers now knew the layout of the structure and the existence of multiple tunnels–some of which were fakes in order to confuse any attackers.