Fans were ready for Robert Downey Jr. when he arrived in Dedham on Thursday to film more of his movie “The Judge.’’ “It’s amazing that he’s real,’’ said Sarah Perno, a Dedham Square Circle intern who got his autograph. Dominic Marcil, 3, and Giovanni Revetria, 2, got their Iron Man masks signed by the superstar. Their mothers, Christin Leger and Katie Revetria, brought them from Lunenburg and Leominster, respectively. Dedham was chosen for exterior scenes of “The Judge,’’ which follows a lawyer (Downey) who returns to his hometown for his mother’s funeral. While there, he discovers his father (Robert Duvall) is a murder suspect. Prior to the filming, the crew of “The Judge’’ altered buildings at the corner of Ames and High streets to fit the movie, which takes place in a town in Crawford County, Ind. The Norfolk County Superior Court became the Crawford County Superior Court, and a similar change was made to the Norfolk County Registry of Deeds. The Dedham Community House became the Willow Brothers Funeral Home and was featured in a scene where Downey drives up to the building, puts on his suit jacket, and walks inside. Scenes for “The Judge’’ have already been shot in Shelburne Falls and Milton. The movie crew will be back in Dedham for more filming on Friday. . . . And that dead body on Good Harbor Beach in Gloucester Thursday? Not real. A crew from the Denzel Washington movie “The Equalizer’’ filmed a scene that involved the discovery of a body on the beach. A few folks on Twitter were initially — and understandably — alarmed.