The FBI have pursued a case on the assault of Salman Rushdie on stage in August 2022.
Hadi Matar, the alleged attacker, appeared in a federal court on Wednesday.
The author was speaking in New York as Matar mounted the stage. He is alleged to have attacked Rushdie with a knife.
Rushdie has since written about his ordeal.
In 1989 Iran issued a fatwa against him because of The Satanic Verses, a book he wrote which offended some Muslims.
