Federal prosecutors want to use letters found in the raid that killed al Qaeda leader Osama bin Laden in their case against a Libyan man believed to have helped orchestrate the 1998 bombings of U.S. embassies in Kenya and Tanzania, the Associated Press reported Monday. Prosecutors claim the letters detail Abu Anas al-Libi’s involvement in al Qaeda, including two letters they said were written by the terror suspect.

Al-Libi was captured in Libya in 2013 and was charged with terrorism offenses, including his alleged involvement in the 1998 East Africa embassy bombings that killed 224 people in Kenya and Tanzania. Prosecutors announced their intention to obtain the letter in a filing Monday in Manhattan federal court, where al-Libi is being tried.

Six letters recovered from bin Laden’s compound, dated between June 2010 and April 2011, are being sought as evidence by prosecutors in al-Libi’s case. Al-Libi wrote two of the letters, according to the AP. Bin Laden was killed in the raid on his compound in Abbottabad, Pakistan, in May 2011 after a nearly 10-year manhunt for the al Qaeda mastermind.

One of the letters was written by al-Libi, also known as Nazih Abdul-Hamed al-Ruqai, to bin Laden in 2010, according to the New York Times. “You may know the place you hold in my heart, and so I ask Allah to bring us together,” he allegedly wrote. Other letters by al Qaeda leaders praise al-Libi and suggest that he gain more responsibility with al Qaeda.

Prosecutors said in court papers that the letters prove that al-Libi had “both the means and the motivation” to communicate with bin Laden and “his ongoing commitment to jihad and achieving martyrdom,” according to the Times.