Notable due process ruling from Massachusetts high court about detaining dangerous juves

Thanks to this post at How Appealing, I discovered yesterday's notable due process ruling coming from the Supreme Judicial Court of Massachusetts.  This article from the Boston Globe provides a useful summary of the ruling:

The highest court in Massachusetts struck down a law yesterday that allows the state to keep juvenile offenders who are slated to be released at 18 in custody for three more years if they are believed to be dangerous....

In yesterday's decision, [the court] wrote that the court warned the Legislature in 2004 that it had "grave concerns" about the constitutionality of the statute because of its failure to adequately define dangerousness, and "invited it to correct the deficiencies."  However, the Legislature did not change the law.  

The court found that the current law has "potential for abuse of unlimited discretion."  The DYS first makes a determination of dangerousness and then submits its recommendation to civil court, where a judge or jury ultimately decides whether the teenager should remain in custody.

Though limited to a specific factual setting, the court's expressed concerns about vagueness and limited procedural protections in the assessment of "dangerousness" could have implications in lots of other settings.  And, importantly, the court here made clear that its ruling was that the state "statute violates substantive due process" under the 14th Amendment.  Anyone concerned with the very concept of "substantive due process" may be concerned with the implications of how this court justified its holding.