Webber's role on the J. J. Abrams-produced "11.22.63" was his first in the United States. He got the role after sending in an audition tape, which he had two days to prepare for, including watching newsreels of Oswald and listening to clips of his voice. After he was cast, he then read the novel on which it was based, as well as other books about the assassination. Webber received praise for "mastering Oswald's peculiar speech pattern and growing sense of paranoia."