"If I'm wrong," he said, "an appeals court can figure it out."
And it no doubt will.
It's one of many sometimes-conflicting ways that judges, public defenders, prosecutors, and prison officials are interpreting the ruling and scrambling to catch up to it. And Rice is facing one of the mind-numbing consequences: a life-with-parole sentence in a state that doesn't allow parole in life sentences.
It's an unprecedented challenge. The ruling affects nearly 500 juvenile lifers in Pennsylvania, about 300 of them from Philadelphia.
The Philadelphia District Attorney's Office expects individual resentencing hearings will be required.
To buy time to accomplish that, the district attorney wrote a letter to the U.S. District Court for the Eastern District, asking it to dismiss - or at least stay - each of 218 federal petitions filed by juvenile lifers from Philadelphia. Those cases, seeking relief following the 2012 decision, Miller v. Alabama, had been in limbo until Montgomery could be decided.
Now, it's likely a single judge will be appointed to oversee the process, according to the letter.
Bradley Bridge of the Defender Association of Philadelphia said he hopes to resolve a "significant number" of cases by agreement between the defendants and prosecutors. He said agreements are most likely for inmates who have been in prison the longest, like Joe Ligon, who has served 63 years for crimes committed when he was 15.
"If it's not a significant number, it's going to be complicated, messy, and really unwieldy," he said. "To have 300 hearings . . . we simply don't have the resources."
Bridge and others have organized a series of training sessions for lawyers on presenting mitigating evidence; the first was so popular, they had to turn people away.
Each hearing will require extensive collection of records, individual assessments, and reentry plans. Some inmates may even have to prove that they were actually younger than 18 at the time of the crime.
"It's an unprecedented moment in criminal justice history in the United States and in Philadelphia in terms of the number of cases that require a serious second look," said Marsha Levick, a Juvenile Law Center attorney who was cocounsel in Montgomery.
One thing that does seem evident to prosecutors and defense lawyers in Philadelphia, at least, is that simply changing sentences to life with parole is not permissible under state law.
"We can't parole anybody who has a life sentence," confirmed Laura Treaster, a spokeswoman for the state's Board of Probation and Parole.
What that means for juvenile lifers such as Rice - who was 17 when he snatched a woman's purse, causing her to fall, hit her head, and later die - is unclear. MacElree revised the sentences of five men altogether. At least one of them, Martin Knecht, has already appealed to Superior Court.
Treaster said, "We're waiting for further instructions from the courts or from the legislature about how we're supposed to process these cases."
The Department of Corrections has been holding focus groups with juvenile lifers to ensure they have the paperwork and treatment programs to apply for parole should they become eligible. It reports 329 of 480 juvenile lifers have completed programming, while 37 are enrolled and 83 are awaiting or have refused programs.
Jennifer Storm, the state's victim advocate, has also been preparing: keeping victims' families informed, and seeking out other victims who haven't yet registered with her office.
There are 328 registered victims across the state affected by Montgomery.
"Maybe three," she said, are ready to see the perpetrators freed. "The overwhelming majority is very angry. They are frustrated. They feel betrayed by the courts."
Still, inmates are preparing to make their case.
Anita Colon of Swarthmore said her brother Robert Holbrook, 42, is cautiously optimistic. On his 16th birthday, he was involved in a drug deal in which someone was shot and killed. To her, that feels like a lifetime ago.
"We want to show who he has evolved to as a man in prison," she said.