reasonable presumption against waiver should be indulged. Commonwealth v. Hooks, 375 Mass. 284, 288 (1978). A defendant’s illiteracy or low intelligence is not dispositive of his capacity to waive Miranda rights and render a knowing, intelligent, and voluntary confession. See Commonwealth v. Ostrander, 441 Mass. 344, 346, cert. denied, 543 U.S. 867 (2004); Commonwealth v. Jackson, 432 Mass. 82, 86-87 (2000) (concluding that the defendant, who had a learning disability and an IQ in the eighties, validly waived his rights in light of his “considerable prior experience with the police and in receiving Miranda warnings,” as well as his “cunning” attempts to exculpate himself “after being confronted with the [ ] evidence against him”); Commonwealth v. Hartford, 425 Mass. 378, 380-81 (1997) (<HOLDING>); Commonwealth v. Dingle, 73 Mass.App.Ct. 274,
holding that a 15yearold was of suitable intelligence and maturity to validly waive miranda rights specifically focusing on the fact that the juvenile had been advised of his rights on three prior occasions and had once asked for an attorney recognizing that plaintiffs had standing to allege infringements of their first amendment rights where the record established that they had been threatened with enforcement of the statute and that such enforcement would cause them injury holding that language difficulties may impair the ability of a person in custody to waive his miranda  rights in a free and aware manner holding admissible suspects statement to police after being informed that he had been identified in a lineup which the court assumed without deciding was interrogation for purposes of the appeal because the statements were voluntarily made without any coercion and came after the suspect was given and validly waived his miranda rights holding that irrespective of the suspects limited reasoning ability and iq of 73 evidence that the suspect had held various parttime jobs had been living on his own possessed a drivers license and had prior experience with law enforcement was probative of competence to waive miranda rights