Extensive authority provides that an ineffective assistance of counsel claim can be defeated by the failure of the habeas petitioner to prove either the deficient performance or resulting prejudice prongs of the standard in the 1984 U.S. Supreme Court case of Strickland v. Washington. Vance Johnson, convicted of murder and criminal possession of a firearm, appealed from the habeas court's judgment denying his fourth petition for a writ of habeas corpus. The petitioner alleged ineffective assistance of counsel in his underlying criminal trial and two earlier habeas proceedings based on the failure of his trial counsel, Fred DeCaprio, to request a competency examination under C.G.S. §54-56d and the failure of his two prior habeas attorneys to allege ineffectiveness by their predecessors in prior trial and habeas proceedings. The Appellate Court affirmed the judgment. In determining that the petitioner failed to prove that his attorneys rendered ineffective assistance, the habeas court credited the testimony of each of the petitioner's attorneys, as it was free to do, that they never had any reason to question the petitioner's competency at the time of trial. Based upon that testimony, the habeas court determined that there was no ineffectiveness of counsel as claimed and thus that the petitioner failed to satisfy the first prong of Strickland. The habeas court's conclusion was amply supported by the record. No error was found. The petitioner's claim was rejected that the habeas court improperly denied his request to admit into evidence the report and testimony of his medical experts on competency. The habeas trial was bifurcated over the petitioner's objection and the habeas court did not reach the issue of prejudice. The petitioner unsuccessfully asserted that when the issue before the habeas court is whether counsel was ineffective for failing to request a competency examination, the performance and prejudice prongs of Strickland are intertwined and that the court should have permitted the evidence. The claim was found contrary to extensive authority that an ineffective assistance claim can be defeated by the failure of the petitioner to prove either deficient performance or resulting prejudice. The habeas court properly applied Strickland's test.