Murgia (P) was an officer in the Uniformed Branch of the Massachusetts State Police. The Massachusetts Board of Retirement retired him upon his 50th birthday. P sued alleging that the operation of § 26(3)(a) denied him equal protection of the laws. The District Judge dismissed P's complaint on the ground that the complaint did not allege a substantial constitutional question. On appeal, the Court of Appeals set aside the District Court judgment and remanded the case. The three-judge court filed an opinion that declared § 26(3)(a) unconstitutional on the ground that 'a classification based on age 50 alone lacks a rational basis in furthering any substantial state interest,' and enjoined enforcement of the statute. On the equal protection claim, the Court found it unnecessary to apply a strict-scrutiny test because that the age classification could not, in any event, withstand a test of rationality. The District Court held that compulsory retirement at age 50 was irrational under a scheme that assessed the capabilities of officers individually by means of comprehensive annual physical examinations.