What is the test for admitting statements of co-conspirators against a criminal defendant?

The order of taking evidence may vary, but prior to the final admission of out-of-court statements of co-conspirators against a criminal defendant to the fact finder, the government must establish by a preponderance of the evidence that a conspiracy existed and that the defendant was connected to it. Bourjaily v. United States, --- U.S. ----, 107 S.Ct. 2775, 2778-79, 97 L.Ed.2d 144 (1987) (Bourjaily ). The existence of a conspiracy and the defendant's involvement in it are preliminary questions of fact that must be resolved by the trial court. Id. 107 S.Ct. at 2778.