Michael Adebolajo said he handed a letter to an eyewitness of the attack in Woolwich to make it clear that the events happened "for one reason and one reason only - that's foreign policy".
He told the court: "The life of this one soldier might save the lives of many, many people, not just from Muslim lands but from this country."
Adebolajo said he asked people at the scene at Woolwich Barracks to film him to "make it clear to everybody why the soldier lost his life" and "how this can be avoided in the future".
In her only television interview since the verdict, she told ITV News that she begs forgiveness from Lee Rigby's family.
A mother and daughter who witnessed the attack on Lee Rigby have told ITV News how they are still haunted by what they saw that day.
Lee Rigby's sister told ITV News that she wishes she had not talked her brother out of returning to Afghanistan shortly before his death.