A man accused of having ties to two terrorist groups pleaded guilty in December 2011 and has been cooperating with the government, the Justice Department revealed Monday.

Ahmed Abdulkadir Warsame pleaded guilty to nine terrorism charges and could go to prison for the rest of his life.

He was a leader of the Somali terror group Al-Shabaab and arranged a weapons deal with the Yemen-based al Qaeda in the Arabian Peninsula, according to the U.S. attorney for the Southern District of New York.