[14, 15] Moreover, we have historically mandated, under article 15, more protection for a suspect's rights where Miranda is concerned than has the United States Supreme Court. For example, we require proof of a waiver to be established beyond a reasonable doubt, see State v. Derby, 131 N.H. 760, 761, 561 A.2d 504, 504 (1989); State v. Gullick, 118 N.H. 912, 915, 396 A.2d 554, 555 (1978), and we have established special rules for evaluating waivers by juveniles, State v. Benoit, 126 N.H. 6, 17-19, 490 A.2d 295, 302-04 (1985). If we are to remain faithful to our tradition of implementing the right against self-incrimination through rigorous enforcement of the Miranda safeguards, we must ensure that the police are not provided an incentive for disregarding these rights.