The ISIS spy who betrayed al-Baghdadi was an insider motivated by revenge

NORTHERN SYRIA — The Islamic State militant group's leader Abu Bakr al-Baghdadi was betrayed by a member of his inner circle who helped lead American troops to his compound in northern Syria.

The commander of the Kurdish-led Syrian Democratic Forces, Gen. Mazloum Abdi, gave NBC News a detailed account of how he spent months running a spy inside ISIS who followed al-Baghdadi as he moved from one safe house to another, until he was finally trapped in a tunnel beneath one of them.

Abdi did not identify the source, but Kurdish intelligence officials described him as an Arab who had many relatives in ISIS.

Abdi said the informant’s main motivation was revenge.