Commonwealth v. Smith, 471 Mass. 161

In June 2007 a 17-year, 5-month-old defendant was arrested after a shooting that killed a 14-year-old; police found a jammed handgun in a car where the defendant had been sitting and ballistics linked the gun to the scene.
At the Brockton police station, officers read Miranda rights, provided a waiver form (which the defendant initialed and orally waived), and interrogated him; after initially denying involvement he later implicated himself and named another person as the shooter.
The defendant moved to suppress his statements, arguing his waiver was invalid because he was not given a meaningful opportunity to consult with an "interested adult" under Massachusetts common law protections for juveniles.
The Superior Court denied suppression, finding (beyond a reasonable doubt) the waiver voluntary and intelligent and that the interested-adult rule did not apply to a seventeen-year-old.
The Appeals Court affirmed; the Supreme Judicial Court granted further review limited to the interested-adult rule issue and affirmed the conviction.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether the common-law "interested adult" rule required suppression of statements by a 17-year-old who waived Miranda rights	Commonwealth: Interested adult rule does not apply to 17-year-olds; waiver was voluntary and intelligent	Smith: As a 17-year-old, he should have had meaningful opportunity to consult an interested adult before waiving Miranda	Held: Rule did not apply to defendant; waiver valid beyond a reasonable doubt; conviction affirmed
Whether the 2013 statute expanding "juvenile" to include 17-year-olds applies retroactively to require suppression	Commonwealth: 2013 act is prospective and does not alter common-law rule; no retroactive effect	Smith: 2013 act shows legislative intent to treat 17-year-olds as juveniles and entitles him to interested-adult protection	Held: 2013 act applies prospectively only and does not change the common-law interested-adult rule for past interrogations
Whether the court should extend the interested-adult rule to 17-year-olds and, if so, whether extension should be retroactive	Commonwealth: Extension not required; if made, should be prospective for fair notice	Smith: Extension should apply to his case (or at least contemporaneous cases)	Held: Court extends the rule to 17-year-olds prospectively only; not applied to this defendant

Miranda v. Arizona, 384 U.S. 436 (1966) (establishes custodial warning and waiver framework)
Commonwealth v. A Juvenile, 389 Mass. 128 (1983) (established interested-adult protections for juveniles under 14 and consultation opportunity for ages 14–17)
Commonwealth v. Berry, 410 Mass. 31 (1991) (heightened burden to prove knowing, intelligent waiver by juveniles)
Commonwealth v. Guyton, 405 Mass. 497 (1989) (discusses juvenile waiver issues and interested-adult consultation)
Commonwealth v. Philip S., 414 Mass. 804 (1993) (describes interested-adult rule as a prophylactic common-law protection and the need for definite procedures)
Commonwealth v. Watts, 468 Mass. 49 (2014) (construed the 2013 statutory changes as prospective)
Commonwealth v. Simon, 456 Mass. 280 (2010) (noting interested-adult rule goes beyond constitutional minima)