Moreover, it cannot be doubted that the doctrine of Blohm supplies Wingo with these presumptions of line-of-duty disability. Monica v. Tobriner, 253 F. Supp. 851, 852-853 (D.D.C. 1966). We think that under Blohm the Government's view, that the police officer's disabling condition was not related to his service, must not only be supported by substantial and persuasive evidence, but must also be supported by findings of the Retirement Board setting forth the material facts.

Even were we to conclude that the proximate cause of petitioner's disability was doubtful or external to his service, the record unmistakably demonstrates the requisite degree of aggravation to fall within the statutory scheme.See D.C. Code 1975 Supp., § 4-527(2); Crider v. Board of Appeals and Review, supra; see also Monica v. Tobriner, 253 F. Supp. 851 (D.D.C. 1966). We find no substantial support for the Board's conclusion that petitioner's disability was unrelated to his police service.