NBCNews.com published this story of a devastated father losing his son to ISIS.

In his small Silicon Valley office, Salem Khan covered his face with his hands and sobbed deeply.

He was crying about his 24-year-old son, Jaffrey, a troubled young man who had struggled in school and in life. Khan long feared his child would one day do something terrible — and now he had.

He had joined ISIS.

With his wife and 18-year-old brother-in-law in tow, Jaffrey left…and offered his services to one of the most savage terrorist organizations in the world.