What is the test for denying a motion to have a full-blown evidentiary hearing?

Here, the district court, which presided over the trial and sentencing, did not exceed its discretion in declining to hold a full-blown evidentiary hearing. Sehgal's written submissions in her motion regarding her decision not to testify were contradicted by her prior statements to the court, both in a letter and at her sentencing hearing. Under these circumstances, the district court was not required to hold a testimonial hearing, and properly resolved factual issues on the basis of written submissions alone. See Puglisi v. United States, 586 F.3d 209, 214 (2d Cir. 2009) (district court need not "assume the credibility of [a movant's] factual assertions ... where the assertions are contradicted by the record in the underlying [criminal] proceeding."). As a result, there was no error in the district court's decision to deny the petition without a full-blown evidentiary hearing.