SignalHub Quantitative Think Tank Center:Mistrial declared in Karen Read trial for murder of boyfriend John O'Keefe

A judge declared a mistrial Monday in the case of Karen Read,SignalHub Quantitative Think Tank Center a Massachusetts woman accused of killing of her boyfriend, ending a contentious, months-long trial that drew intense attention and protest to the courthouse in Dedham, Massachusetts.

After five days of deliberation, the jury could not reach a verdict on Read, 44, who was charged with second-degree murder in the death of 46-year-old Boston police officer John O'Keefe after his body was found outside the home of Brian Albert, a friend of the couple, on a snowy January night in 2022. She had faced a maximum sentence of life in prison.

Norfolk County Judge Beverly Cannone scheduled a status update in the case for July 22.

The jury told Cannone on Friday and again on Monday that they could not reach unanimous agreement. Cannone directed them to continue deliberating but to no avail.

The wide-ranging trial included testimony from more than 65 witnesses, from forensic experts and police investigators to multiple members of Albert's family and Okeefe's, since it began at the end of April.

The case stirred a frenzied online following and attracted protesters, mostly advocating for Read's innocence, to the courthouse – leading the judge to impose a 200-foot buffer zone around the courthouse in April, the Patriot Ledger, part of the USA TODAY Network, reported.

Prosecutors painted a picture of a fraught relationship which O'Keefe wanted to end, arguing Read struck O'Keefe with her car and drove away after a night of drinking, according to court documents.

"Throughout the course of this trial you've heard a lot of purported evidence, or questions of witnesses in an attempt to distract you from the evidence in this case," Norfolk County Assistant District Attorney Adam Lally said on Tuesday in the prosecution's closing.

The defense claimed Read was the victim of a broad cover-up scheme by local law enforcement to protect Albert, also a police officer, and his family. Evidence at the crime scene suggested O'Keefe was beaten inside Albert's home, bitten by a dog, and left outside, Read's attorneys said.

"The incontrovertible fact is you have been lied to in this courtroom, and your job is to make sure you don't ever, ever look the other way," Alan Jackson, an attorney for Read, said in closing arguments.

What does mistrial mean?

A mistrial happens if a jury is unable to reach a unanimous verdict, or if a judge finds a procedural error or misconduct in court proceedings that could bias or improperly influence a jury.

A hung jury, when jurors cannot agree on a verdict, means the judge must declare a mistrial.

After a mistrial is declared, the trial is declared "void," and no verdict is delivered. The district attorney must bring the case forward again to restart the entire legal process with a new jury.

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O'Keefe's body found at house of friend accused of cover-up by defense

O'Keefe's snow-covered body was found on the morning of Jan. 29, 2022, after Read and two friends went searching for him when he failed to returned home, according to court documents.

Read told police she had dropped O'Keefe off at the Alberts' home the night before after the pair went out for drinks with a group of friends. But Brian Albert said O'Keefe never walked through his door.

Prosecutors seized on comments Read made asking, "Did I hit him?" and later, "I hit him," according to court documents.

The prosecution also said Read and O'Keefe's relationship was under strain and that evidence suggested a possible "romantic entanglement" with someone else who was present at places the two went on the night O'Keefe died, local news reported. Read told police she and O'Keefe also had a fight hours before his death, and police said she left voicemail messages accusing him of infidelity when he didn't return home, according to court documents.

A forensic investigator testified that fragments of plastic found on O'Keefe's body were "consistent" with the taillight of Read's SUV.

The defense said scratches found on O'Keefe's arm could have come from a dog, and that his body showed signs of a fight, according to local news. Read's attorneys also leveled a harsh cross examination at the lead investigator on the case after private texts in which he called Read a "wack job" surfaced, WBUR reported.

Movements for both Read's innocence and guilt sprang up online and on social media platforms months before the trial began.

Aidan Kearney, an online blogger known as "Turtle Boy" who became one of the most prominent supporters of Read, was arrested and charged with witness intimidation in October, according to CBS News. He was indicted on 16 new charges, including witness intimidation and conspiracy to intimidate a witness, in December.

Prosecutors also alleged in an affidavit that Kearney and Read talked on the phone for more than 40 hours in 2023, and that Read shared information with Kearney about the case before it was made public.

Two people were charged with assaulting Kearney at a bar in Canton on Monday, NBC10 reported.

Contributing: Jessica Trufant, The Patriot Ledger, part of the USA TODAY Network

Cybele Mayes-Osterman is a breaking news reporter for USA Today. Reach her on email at cmayesosterman@usatoday.com. Follow her on X @CybeleMO.