CBS News has obtained a photo of the man who would become the leader of the Islamic State of Iraq and Syria (ISIS) while he served time at a U.S. military prison in Iraq in 2004.

CBS News

In the photo, Abu Bakr al-Baghdadi is pictured while being in-processed at Camp Bucca in early 2004. He appears to be wearing the same yellow prison jumpsuit worn by other prisoners there.

A previous CBS News investigation revealed that Baghdadi was among at least 12 of the top leaders of ISIS who served time at Bucca, one of the toughest, American prisons in Iraq. Baghdadi spent 10 months at the prison, from February to December 2004.

CBS News has learned Baghdadi was nabbed at a meeting with other suspected insurgents and was transferred to the prison within several days of his capture. He was detained because the U.S. believed releasing him could jeopardize other military operations.

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Baghdadi was employed as a university official at the time of his capture on February 4, 2004.

U.S. officials who worked at Bucca previously told CBS News they were concerned that prisoners were becoming radicalized. The prison has been described as "a pressure cooker for extremism."

The U.S. set up a rehabilitation program at Bucca to try to combat extremism, but some who worked there have said that it wasn't implemented effectively.

The reclusive Al-Baghdadi has made only one public appearance since declaring himself caliph, delivering a June sermon at a mosque in Mosul. In November, a purported audio of the ISIS leader emerged, in which he urged his followers to "explode the volcanoes of jihad everywhere."