Court records show Waide got a judge's permission to withdraw as Curtis' attorney in January 2001. Waide said he withdrew from the case because Curtis didn't trust him.
"He thought I was conspiring against him," Waide said. "He thinks everybody is out to get him."
The FBI said there was no indication of a connection between the letters and the Monday bombing in Boston that killed three people and injured more than 170. The letters to Obama and Wicker were postmarked April 8, before the marathon.