Authorities used an undercover informant who befriended Bujol and, posing as a recruiter for Al Qaeda in the Arabian Peninsula, offered to help him travel to the Middle East. The informant wasn't a law enforcement agent.

Authorities said Bujol had previously made three unsuccessful attempts in 2009 to travel to Yemen or elsewhere in the Middle East.

Prosecutors also alleged Bujol exchanged emails with the U.S.-born cleric, Anwar al-Awlaki, who had ties to Al Qaeda.

Al-Awlaki, killed by a U.S. drone strike in September in Yemen, is also believed to have exchanged emails with Maj. Nidal Hasan, the Army psychiatrist charged in the killing of 13 people in the November 2009 shootings at Fort Hood in Texas.

According to court documents, Bujol used at least 14 email addresses to hide his activities from authorities and he advocated attacking U.S. facilities where military weapons were manufactured.