Federal authorities in Colorado are reviewing a 2002 file on a Muslim cleric who communicated with the shooting suspect at the Fort Hood Army base in Texas.
The U.S. Attorney's Office in Denver confirmed Tuesday that it has some record of Anwar al-Awlaki.
An official won't confirm a report by ABC News that the file is about a felony warrant issued on a passport fraud charge but then revoked by the Colorado U.S. Attorney's Office.
Al-Awlaki is a New Mexico native who graduated from Colorado State University in Fort Collins, Colo., in 1994 with a bachelor's degree in civil engineering. In 2002, he moved to Yemen, where he is at large.
The imam was reportedly corresponding by e-mail with Maj. Nidal Malik Hasan, who is charged with killing 13 people at Fort Hood last month.