The second-degree murder trial of Massachusetts woman Karen Read has come to an end − for now.

The 44-year-old Mansfield woman was accused of killing her Boston police officer boyfriend, 46-year-old John O'Keefe, after he was found dead in the snow on a fellow officer's lawn on the morning of Jan. 29, 2022.

While the prosecution alleged that Read struck O'Keefe with her car after a night of drinking and then fled, the defense, headed by heavy-hitter attorney Alan Jackson, instead made the case that Read was a convenient scapegoat in a coverup initiated by local law enforcement.

After several weeks of testimony, the trial came to a somewhat unsatisfying conclusion when a mistrial was announced on Monday due to a hung jury.

While community opinions on the matter appear split, Read has galvanized some in the court of public opinion, with many supporters spotted holding signs outside of the courtroom in solidarity with her.

The case has garnered national attention for its many twists and turns and lively testimony. Here's an overview of the major beats of the case, as reported by the USA TODAY Network and local media.

January 28, 2022

On the evening of Jan. 28, 2022, a group met in Canton, Massachusetts, for a Friday night out.

Despite a heavy snowstorm, Boston Police Officer John O'Keefe went out drinking at C.F. McCarthy's bar with his girlfriend, Karen Read, and friends and coworkers, including fellow Boston Police Officer Brian Albert, and his sister-in-law, Jennifer McCabe.

Between around 11 p.m. and midnight, the group moved to the nearby Waterfall Bar & Grille.

January 29, 2022 - John O'Keefe's death

Read drove O'Keefe to the home of Brian Albert where a group decided to meet after the bar. She had allegedly been drinking before giving O'Keefe the ride after midnight, according to the prosecution.

Between 12:15 and 12:45, multiple witnesses reported seeing a dark SUV outside of the home but that no one came inside. Read had been texting O'Keefe but failed to receive responses to her final four texts, sent between 12:31 and 12:45 p.m. according to the defense.

Between 4 and 5 a.m., Read and O'Keefe's niece contacted Jennifer McCabe saying O'Keefe had never come home and was not answering his phone. Kerry Roberts, a friend of O'Keefe's, went out with McCabe and Read to look for him.

Around 6 a.m., O'Keefe was spotted lying unresponsive in the snow on Albert's lawn. First responders were called.

 At 7:59 a.m.,O'Keefe was pronounced dead at Good Samaritan Hospital.

January 31, 2022 - Autopsy shows blunt impact injuries

An autopsy completed on O'Keefe found his cause of death to be consistent with blunt impact injuries to the head and hypothermia. The medical examiner ruled there were no "obvious signs of an altercation or a fight."

February 1, 2022 - Karen Read arrested

Karen Read is arrested and charged with motor vehicle homicide, manslaughter and leaving the scene of a motor vehicle collision causing death. She pleads not guilty in Stoughton District Court the following day.

June 9, 2022 - Karen Read indicted

Karen Read is indicted by a Norfolk County grand jury and arraigned on charges of second-degree murder, manslaughter while operating under the influence of alcohol, and leaving the scene of personal injury and death.

The following day, she pleaded not guilty at Norfolk Superior Court and was held on $100,000, which she soon after posted.

September 22, 2022

Read's defense begins introducing ideas that will become central to their case to the court, alleging that evidence alludes to a cover-up by the Canton Police Department and Massachusetts State Police.

April 12, 2023 - 'Hos long to die in cold' Google search

The defense publicly releases what it calls "bombshell exculpatory information," most notably a Google search allegedly made by Jen McCabe at 2:27 a.m. the morning O'Keefe died asking "hos (sic) long to die in cold."

Later, the prosecution would claim these searches were made after 6:23 a.m. and 6:24 a.m. after O'Keefe was found, while the defense argued that a federal forensic expert placed the search at 2:27 a.m., long before authorities were notified of O'Keefe's death.

August 24, 2023

Norfolk County District Attorney Michael Morrissey made an unusual move in issuing a video statement on accusations made by the defense, saying they were "baseless" and "conspiracy theories" that constituted harassment of people involved in the case.

"The idea that multiple police departments, EMTs, Fire personnel, the medical examiner, and the prosecuting agency are joined in, or taken in by, a vast conspiracy should be seen for what it is - completely contrary to the evidence and a desperate attempt to re-assign guilt," he said.

October 11, 2023 - 'Turtle Boy' arrested

"Turtle Boy," AKA Aidan Kearney, is arrested for information posted on his blog "Turtleboy News." Kearney wrote about the case often and was charged with witness intimidation and conspiracy due to his practice of confronting witnesses on camera.

Kearney, who sold "Free Karen Read" merch and fundraised toward her defense fund, was later indicted on eight counts of witness intimidation, three counts of conspiracy to intimidate witnesses and five counts of picketing a witness. Later, he would return to court and have his bail revoked for assault and battery charges from an ex-girlfriend.

He has denied all charges against him. Karen Read was accused of having close contact with Kearney and feeding him information.

November 20, 2023

The residents of Canton, Massachusetts, vote 903-800 to audit the Canton Police Department, reports local media. The split in votes paints a picture of a community divided over the case.

February 22, 2024

Prosecutors finally introduce the anticipated results of the crime scene evaluation, saying DNA belonging to O'Keefe was found on a broken taillight from Read's vehicle.

February 26, 2024

Federal prosecutors release over 3,000 pages of evidence, delaying the start of the trial from March 12 to April 16.

March 13, 2024 - Trooper under investigation

The Massachusetts State Police announced they opened an internal investigation into Trooper Michael Proctor, the leading investigator on the Read case. In a brief press statement, the department says it is looking into "a potential violation of department policy."

Read's defense alleged that Proctor hid personal ties to the case and the people involved. Proctor's attorney denied any wrongdoing.

March 28, 2024

Judge Beverly J. Cannone denies the defense's motion to dismiss the case against Read, citing "extensive evidence supporting the indictments."

April 16, 2024 - Karen Read trial begins

Jury selection for Karen Read's second-degree murder trial begins.

April 29, 2024 - Karen Read trial begins

Opening statements are delivered and testimony begins with the first witnesses, John O'Keefe's brother, Paul, and his wife, Erin.

The prosecution rounded out the first day of testimony with Canton police officer Steve Saraf, who responded to the scene of O'Keefe's death.

April 30, 2024 - Responding medic testifies

A Canton paramedic who responded to the scene testifies, saying he heard a woman repeating "I hit him, I hit him." The defense challenged this retelling of events, saying the testimony around what was said has changed multiple times.

A few days later, four paramedics and firefighters would testify to what they saw the day O'Keefe was found.

May 17, 2024 - Jennifer McCabe takes the stand

Jennifer McCabe takes the stand for the first time as a key witness. She alleges the Google search about dying in the cold found on her phone was done at the behest of Read the morning O'Keefe was found.

June 10, 2024 - Michael Proctor takes the stand

Massachusetts State Police Trooper Michael Proctor takes the stand. Over the course of two days, he is grilled for derogatory text messages about Read sent during the investigation, which he is made to read out loud.

June 21, 2024

The prosecution rests its case.

June 24, 2024

The defense rests its case after calling three witnesses.

June 25, 2024 - Karen Read jury deliberation begins

Closing arguments are presented and jurors begin deliberation.

June 26, 2024

The jury leaves after a second day of deliberation without a verdict. Read's attorney has a tense exchange with Judge Cannone about the verdict slip, which lacks a spot for jurors to check "not guilty" for some charges.

After a terse back-and-forth, Cannone has the slips changed.

June 28 - Karen Read jury deadlocked

Jurors send a note to the judge saying they are deadlocked. Judge Cannone tells them to continue deliberating, as she believes they have not spent enough time doing so yet.

July 1 - Karen Read trial ends in mistrial due to hung jury

The jury sends another note saying they are still deadlocked and "deeply divided." After a final attempt at deliberation, a mistrial is declared due to a hung jury.

A mistrial occurswhen a trial is terminated and considered void due to a jury's inability to reach a verdict or a procedural error. In this case, the mistrial was the result of a hung jury, which happens when a jury cannot agree upon a verdict after an extended deliberation.

The Norfolk District Attorney is set to retry the case.

Hours later, the Massachusetts State Police announces that Trooper Michael Proctor has been "relieved of duty."

Key characters in the Karen Read trial

• Karen Read: The 44-year-old woman accused of killing her Boston police officer boyfriend John O’Keefe in 2022.
• John O'Keefe: O'Keefe was 46 and a 16-year veteran of the police force when he died after a night out with his girlfriend and friends. His body was found in the lawn of fellow Boston police officer, Brian Albert.
• Brian Albert:  A fellow Boston police officer, Albert was among the friend group drinking with O'Keefe the night he died. O'Keefe's body was found outside Albert's home.
• Jennifer McCabe: Albert's sister-in-law Jen McCabe became central to the trial not only because she was present at Albert's home the night O'Keefe died, but also because she allegedly made a search about how long it takes to die in the cold in the early morning hours of Jan. 29.
• Michael Proctor: The Massachusetts State Police trooper who led the investigation in the Read case. He has since been dismissed from the police force.
• The Albert Family: Several other members of the Albert family, many of whom are involved in the police force, were called in to testify about the night O'Keefe died, including Brian Albert's brother, Kevin, who is a Canton Police Department detective.
• Brian Higgins: A friend of Albert and an agent for the U.S. Bureau of Alcohol, Tobacco, Firearms, and Explosives. He was allegedly at the Albert home the night before O'Keefe died and was cited by the prosecution as a potential alternative suspect in O'Keefe's death.
• Alan Jackson: Karen Read's defense attorney who gained recognition throughout the trial for his heavy-hitting track record and intense lines of questioning.
• David Yannetti: Another of the leading members of Read's defense team.
• Norfolk Superior Court Judge Beverly Cannone: The judge overseeing the Karen Read case. Prior to serving as an associate justice in the Norfolk County Superior Court, she was an associate justice for the Massachusetts District Court in Quincy.