More than six months after the J. Paul Getty Museum in Los Angeles agreed to hand over 40 artifacts to Italy, the criminal trial of its former curator of antiquities lumbers on in Rome. A prosecution witness painstakingly presented the court with photographs and documents on Wednesday in an effort to establish that more than a dozen looted artifacts had made their way into the Getty’s collection. Marion True, the former Getty curator, is charged with conspiring to acquire illicitly excavated antiquities for the museum. Several of the pieces discussed on Wednesday by the prosecution witness, Daniela Rizzo, are now on view at the presidential palace in Rome as part of an exhibition of objects recovered from American museums in the last two years. Ms. Rizzo repeatedly projected an image of an artifact onto a screen next to a photograph of the same piece in a dirt-encrusted, unrestored state. For most of the pieces, she said, acquisition documents provided by the Getty did not cite the object’s provenance. “If it came from an authorized dig, it would say so and give a date,” she said. “The fact that it doesn’t makes you think, doesn’t it?” Ms. True and the American dealer Robert Hecht, who is on trial with her on similar charges, have both proclaimed their innocence. The next trial hearing is scheduled for mid-March.