WASHINGTON – The decision to charge alleged al-Qaida propagandist Adam Gadahn with treason is something of a gamble by the U.S. government, which has not pursued such a case in more than 50 years and has a mixed track record for convictions over the course of American history, according to legal experts and historic accounts.

Gadahn, 28, was indicted Wednesday by a federal grand jury in Santa Ana, Calif., based on his alleged appearance in numerous al-Qaida videotapes calling for the death of Americans and for attacks on U.S. targets.

Many legal experts said that although Gadahn may be a suitable candidate for a treason charge, federal prosecutors may face serious difficulties in securing a conviction if he is ever brought to trial.

Gadahn, a fugitive believed to be living in Pakistan, grew up on a Southern California goat farm, converting to Islam as a teenager and later moving overseas. He allegedly says in one video that U.S. “streets will run red with blood” and in another refers to the United States as “enemy soil.”

“One of the reasons that I think Gadahn was charged was because of his intentional, brazen and conspicuous activities,” said Brian Levin, director of the Center for the Study of Hate and Extremism at California State University at San Bernardino. “All the stars lined up to virtually hand the required elements to prosecutors on a silver platter. … But it’s not a slam-dunk by any means.”

Fewer than three dozen U.S. citizens have ever been charged with treason, which is specifically defined in the Constitution and requires two witnesses or a confession in court for a conviction. The framers – who bristled at England’s frequent prosecution of dissidents for alleged treason – defined it narrowly as “levying war” against the United States or providing “aid and comfort” to its enemies.

The penalties for treason were left to Congress, which set the range of punishment from five years in prison to death.

The roster of previous treason defendants includes former vice president and malcontent Aaron Burr, who was acquitted of attempting to set up his own republic, and abolitionist John Brown, who was hanged for treason after he and his followers captured the federal arsenal at Harpers Ferry. The last flurry of treason cases was prosecuted during and after World War II, culminating in the 1952 conviction of a Japanese American for abusing U.S. prisoners of war.

The Justice Department’s legal arguments in the Gadahn case rely heavily on the “broadcast cases,” a series of treason prosecutions of U.S. citizens providing propaganda services to the Germans or Japanese. The most famous of these involved Iva Toguri D’Aquino, accused of being “Tokyo Rose,” who served six years in prison but was later pardoned after key witnesses recanted.

In the Gadahn case, the Justice Department argues that the defendant’s appearance in five incendiary al-Qaida videos – particularly three recent broadcasts in which he is clearly visible – provide enough evidence to fulfill the Constitution’s witness requirements for treason.