Steven Spielberg was initially reluctant to approach Tom Hanks about taking the part of Carl Hanratty, assuming that he wouldn't be interested in playing a supporting part at this stage in his career. Hanks put him straight by saying that a good part was a good part no matter the size.
Some FBI agents did occasionally chase Abagnale, but he didn't have a relationship with any of them, and he certainly didn't call them every Christmas. As Abagnale himself points out with flawless logic: "Why would I do that? I didn't want the FBI to know where I was."
The FBI officer who was chasing Frank, and was the main inspiration for "Carl Hanratty," was really Joe Shea. Frank Abagnale, Jr. used the pseudonym "Sean O'Reilly" in his book because Joe Shea was still in the FBI. He has since passed away. However, in an online video interview Abagnale said that Hanks met Shea and patterned his performance on him so perfectly that watching Hanks is virtually the same as watching Shea.
The newly-filmed clip from "To Tell the Truth" that opens the movie was based on an actual episode in which Frank was a guest. In that episode, not a single panelist correctly guessed that he was the real Frank Abagnale, Jr. This episode of "To Tell the Truth" can be viewed on YouTube.
Until he saw the results of Leonardo DiCaprio's work, the real Frank Abagnale, Jr. didn't think DiCaprio was "suave" enough to play him.
Max Spielberg: Steven Spielberg's son, sitting behind Leonardo DiCaprio during both parts of the airplane scene.