Does a sentencing judge have to provide an explanation for a sentencing disparity between co-conspirators who plead guilty and those who go to trial?

In United States v. Capriola, this circuit addressed a sentence disparity between co-conspirators who plead guilty and those who went to trial. 537 F.2d 319 (9th Cir.1976). The court observed that the record was not explicit enough to give a reason for the disparity other than the defendants' different decisions whether to exercise their right to trial. Id. at 320. The court held that when the greater sentence may have been based upon a defendant's decision to exercise this constitutional right, "the sentencing judge must record an explanation." Id. at 321.