The United States government (plaintiff) prosecuted John Muscato, Walter Gollender, Charles McDonald, and other conspirators (defendants) for illegal gun manufacture. The government alleged Muscato loaned Gollender a pistol in furtherance of the conspiracy. Following his arrest, Gollender described the distinctively marked pistol to Special Agent Matthew Raffa. Raffa later arrested McDonald and found a pistol matching Gollender's description in McDonald's possession. At trial, Gollender testified he borrowed Muscato's pistol under circumstances implicating Muscato's guilt. Gollender also identified and accurately described the pistol during his testimony, prior to examining the pistol closely on the witness stand or being told that it was the pistol found in McDonald’s possession. Muscato challenged Gollender's credibility. The government then introduced Gollender's post-arrest description of the pistol and Raffa's testimony that he later retrieved a pistol matching the description from McDonald. The jury convicted Muscato, and he filed a motion for new trial in the United States District Court for the Eastern District of New York. Muscato argued Gollender's post-arrest description of the pistol was inadmissible hearsay.