The indictment “expands the scope” of an October 2009 indictment against Mostafa that included nearly identical charges.
In a report on the investigation, FBI special agent Scott Brunner said "Mostafa played a critical role in al-Shabaab, including in its media operations, training of soldiers, and participating in attacks on Somali government forces and African Union troops.”
More specifically, the new indictment alleges that from March 2008 until February 2017, Mostafa personally supported al-Shabaab through the use of improvised explosive devices in attacks in Somalia.
After graduating from college in 2005, Mostafa traveled to Yemen and then to Somalia “where he engaged in fighting against internationally supported Ethiopian forces” then later joined Al-Shabaab, according to the FBI.
In 2011, Mostafa appeared at a news conference with an al-Shabaab leader, purporting to be an al-Qaeda emissary, the FBI report states.
By 2013 the State Department had offered up to $5 million for his arrest.
The FBI has also implicated Mostafa in a Sept. 30 al-Shabaab attack on the Baledogle U.S. military airbase in southern Somalia and an IED assault on an Italian military convoy traveling in the Somali capital of Mogadishu.
“Mostafa continues to play a critical role in planning operations directed against the Somali government and internationally supported African Union forces in Somalia and East Africa,” Brunner noted.
Mostafa faces multiple charges including conspiracy to provide material support to terrorists and two counts of conspiracy to provide material support to a foreign terrorist organization.
The crimes are punishable by up to 55 years in prison.