The highly-watched murder trial of Karen Read, accused of killing her boyfriend, Boston police officer John O'Keefe, ended in a mistrial on Monday when a "starkly divided" hung jury failed to reach a unanimous decision after 27 hours of deliberation. The announcement was made in Norfolk Superior Court in Dedham, Massachusetts by Judge Beverly Cannone.

Read, who denies any involvement in O'Keefe's death, claims that he was killed at a house party involving police and other law enforcement officers. The trial saw 74 witnesses, with 68 testifying for the prosecution, over a span of 29 days.

The Norfolk District Attorney's office plans to retry the case and expressed gratitude towards the O'Keefe family for their dedication to seeking justice, stating in a statement, "The Commonwealth intends to re-try the case."

During their deliberations, the jury sent notes to Judge Cannone expressing their divided opinions, stating, "Our perspectives on the evidence are starkly divided." They acknowledged their efforts to reach a consensus but ultimately deemed it futile due to their differing beliefs and principles.

Judge Cannone, sympathizing with the jury's impasse, declared a mistrial, setting July 22 as the date for the case to come back to court and determine the next steps.

Following the mistrial decision, defense attorney Alan Jackson spoke briefly outside the court, criticizing the prosecution's handling of the case and vowing to continue fighting. However, Read herself did not provide a comment.

Legal experts predict that a retrial could take months, as the case would need to go back to the same pool of jurors in Norfolk County. Finding individuals unbiased by previous knowledge of the case would pose a significant challenge.

Karen Read, 44, from Mansfield, Massachusetts, faced charges of second-degree murder, manslaughter while operating under the influence, and leaving the scene of personal injury and death. If convicted of murder, she could have faced life imprisonment with the possibility of parole.

According to the prosecution's case, Read allegedly hit and killed O'Keefe with her SUV after a night of drinking, leaving him to die during a snowstorm in Canton, Massachusetts. His body was found in the front yard of a home where an afterparty was taking place.

Throughout the trial, the defense argued that O'Keefe was actually killed during a fight at the house party and then dragged outside. They suggested that the investigation into O'Keefe's death had been biased and focused solely on Read.

While the jury's deadlock prevented a clear understanding of their decision-making process, it remains unknown if they reached a consensus on whether Read hit O'Keefe with her SUV or not.

The mistrial outcome leaves the possibility of a retrial open, but given the backlog of other trials, it is uncertain when a new trial could take place. Meanwhile, the support for Read outside the court has been visible, with large crowds of supporters rallying and advocating for her release throughout the trial.