Many people in Massachusetts and beyond have been closely following the second murder trial of Karen Read, who stands accused of killing in 2022 her boyfriend, Boston police officer John O'Keefe, after her first trial last year ended with a mistrial declaration amid a reportedly deadlocked jury.

Read asked the U.S. Supreme Court to intervene on her behalf to block the retrial on double jeopardy grounds, but that request was denied on Monday, and the defendant no longer has any options left to delay justice further, ABC News reported.

She claims that, though no verdict of acquittal was rendered during her first trial, jurors later revealed that they'd unanimously agreed that she was not guilty of two of the three charges pressed against her -- murder and fleeing the scene of a fatal accident.

Mistrial and retrial

Bloomberg Law reported that prosecutors allege that Read, after a night of "heavy drinking" during a major blizzard in January 2022, backed her SUV over her boyfriend O'Keefe and left him to die in the snow, for which she was charged with second-degree murder, manslaughter while operating under the influence of alcohol, and leaving the scene of a collision resulting in death.

Read and her attorneys have insisted that she is not guilty and somebody else was responsible for killing O'Keefe, and that she was framed as part of a law enforcement cover-up of that crime.

The trial judge declared a mistrial last year after the jury was unable to reach a unanimous verdict, and Read now faces the same charges in a retrial that began earlier this month.

Read claims double jeopardy

However, Read and her lawyers now claim that several jurors from the first trial have reached out to reveal that the jury was unanimous that she was not guilty of murder or fleeing the scene, and the only issue upon which there was any disagreement was the manslaughter while operating under the influence of alcohol charge.

The defendant's attorneys assert that the reported unanimity of the jurors should count as an acquittal on those two charges, which would prevent prosecutors from pursuing those same charges against her again under the U.S. Constitution's prohibition against double jeopardy.

The Fifth Amendment states, in the relevant part, that "nor shall any person be subject for the same offence to be twice put in jeopardy of life or limb," meaning somebody can't be charged twice for the same crime -- assuming some sort of verdict was issued on the first go-round.

Rejected by all levels of the court system

According to Justia, Read's motion to dismiss the two disputed charges under the Double Jeopardy Clause was denied by the trial judge, and that decision was later affirmed by the Massachusetts Supreme Judicial Court.

Turning to the federal court system, Read's motion was also denied by a district court and a First Circuit appellate panel, which prompted a last-ditch appeal for intervention by the U.S. Supreme Court, only for that final plea to be rejected as well.

Indeed, Bloomberg Law reported that Read's initial request for a stay was denied on April 9 by Justice Ketanji Brown Jackson, and now so too was her request for certiorari, as per Monday's Order List, which did not provide any details or reasoning for the rejection.

Read has "run out of options"

Having now been denied by the Supreme Court, ABC News observed, Read has "run out of options" to avoid standing trial again over the 2022 killing of O'Keefe.

Her only remaining hope now to avoid a likely lengthy prison sentence will be an actual acquittal by the jury or yet another hung jury and mistrial paired with a decision by prosecutors to not take a third bite at the apple.