The charge of treason was used for the first time in the United States' war on terrorism Wednesday, filed against a California man who appeared in propaganda videos for Al Qaeda.

Adam Yehiye Gadahn, 28, could be sentenced to death if convicted of the charge, which has been used only a few dozen times in U.S. history and not at all since the World War II era. He also was indicted on a charge of providing material support to terrorists.

Gadahn "knowingly adhered to an enemy of the United States, namely, Al Qaeda, and gave Al Qaeda aid and comfort ... with intent to betray the United States," according to the indictment, handed up by an Orange County grand jury.

Click here to read the indictment (pdf)

The suspected Al Qaeda operative has been sought by the FBI since 2004. Based on the indictment, the FBI added Gadahn to its list of most wanted terrorists and offered a $1 million reward for information leading to his arrest or conviction.

Gadahn, who is believed to be in or near Pakistan, is suspected of having attended the terrorist group's training camps in Pakistan and serving as one of its translators. He has become known by his nom de guerre, Azzam al-Amriki, or "Azzam the American."

Gadahn appeared last month in a 48-minute video along with Al Qaeda's No. 2 leader, Ayman al-Zawahri, calling on his countrymen to convert to Islam and for U.S. soldiers to switch sides in the Iraq and Afghan wars.

It was the second time he appeared in the same video with al-Zawahri. In a July 7 video marking the one-year anniversary of the terror attack on London commuters, Gadahn appeared briefly, saying no Muslim should "shed tears" for Westerners killed by Al Qaeda attacks.

Beyond that, authorities believe he is the masked figure who appeared in two previous videos from Al Qaeda, one given to ABC television in 2004 and another a few days before the fourth anniversary of the Sept. 11 attacks.

According to the indictment, Gadahn announced in the 2004 video that he had joined Al Qaeda, "a movement waging war on America and killing large numbers of Americans."

"Fighting and defeating America is our first priority," he said, according to the indictment. "... The streets of America shall run red with blood."

The treason charge carries penalties ranging from a five-year prison sentence to the death penalty, while the charge of providing material support to a designated foreign terrorist organization carries a possible 15-year sentence.

Raised in Southern California on a Riverside goat farm, Gadahn converted to Islam and worshipped at the Islamic Society of Orange County in 1997 before being expelled for attacking one of its leaders.

His mother last spoke to him by phone in March 2001. At the time he was in Pakistan, working at a newspaper, and his wife was getting ready to have a child.

Gadahn's aunt, Nancy Pearlman, declined to comment.