Justice O'CONNOR, with whom Justice BLACKMUN joins, concurring.
I join the Court's opinion on the understanding that a "satisfactory explanation" within the meaning of 18 U.S.C. § 2518(8)(a) cannot merely be a reasonable excuse for the delay; it must also reflect the actual reason for the delay. Thus, as the Court today holds, an appellate court's review of the sufficiency of the Government's explanation for a delay should be based on the findings made and evidence presented in the district court, rather than on a post hoc explanation given for the first time on appeal. See ante at 495 U. S. 267. With this understanding, I agree with the Court that this case should be remanded for a determination whether the Government's explanation to the District Court for the delay -not the explanation offered on appeal -meets the "satisfactory explanation" standard.