Jurors weighing the murder case against Karen Read, the Massachusetts woman accused of running down and killing her police officer boyfriend in 2022, ended the week without a verdict Friday, their fourth day of deliberations after a trial that included dozens of witnesses and allegations of botched detective work.

Read’s defense lawyers argued that the investigation was flawed, with undisclosed conflicts of interest, offensive text messages and a failure to consider alternative suspects. They’ve alleged a conspiracy among law enforcement officers to cover up the death of Boston police officer John O’Keefe at the hands of one of their own and frame Read in his killing.

Regardless of the trial’s outcome, legal experts said, the proceedings exposed an often-hidden side of law enforcement that can be rife with problems.

“One of the legacies of the Karen Read murder prosecution is that it puts a spotlight on some of the flaws and missteps in the police investigation,” said Daniel Medwed, a professor of law and criminal justice at Northeastern University and an expert on wrongful convictions.

“If there are missteps and sloppiness in a murder investigation involving the death of a police officer, what does that suggest about the process in a more run-of-the-mill case with a civilian victim?” he said.

“This should be cause for concern and some evaluation,” he added.

Stara Roemer, a former Dallas County prosecutor turned criminal defense lawyer in Texas, said the actions of the lead investigator in the case, Massachusetts State Trooper Michael Proctor, reflect a problem with some police officers who show little respect for the subjects of an investigation.

At trial, Proctor acknowledged making derogatory comments about Read and sharing details about the investigation with friends and family. He testified that the comments were unprofessional but did not compromise the investigation.

“I have never seen this kind of an appearance of impropriety,” Roemer said. “I am sure that this happens every day. The difference between this case and other cases is that, generally, the detectives going home and talking to whoever about a case — they’re not talking about it with people who know the people that are involved in the case and are potential suspects.”

“If I were a police officer and I saw this, it’s like, how are you expected to go out and do your job?” she added. “How do you trust the police?”

The Massachusetts State Police did not respond to a request for comment. A message left on a number listed for Proctor was not returned.

A night out and an after-party 

Read and O’Keefe, 46, who had been a Boston police officer for 16 years, had been at a bar with other current and former law enforcement officers the night before he was found dead. O’Keefe had planned on going to an after-party at the home of a now-retired Boston police sergeant, prosecutors have said, but never made it inside.

O’Keefe was discovered in the front yard of Brian Albert’s home around 6 a.m. on Jan. 29, 2022.

He was later pronounced dead at a local hospital. The medical examiner attributed his cause of death to blunt force trauma to the head and hypothermia, and Read was later charged with second-degree murder, vehicular manslaughter and other crimes. She pleaded not guilty.

Prosecutors have alleged that Read — drunk and angry over her troubled relationship with O’Keefe — backed her SUV into her boyfriend while dropping him off at the after-party.

At trial, Norfolk County Assistant District Attorney Adam Lally said vehicle data from Read’s Lexus showed her SUV traveled backward for 60 feet at 24 mph outside Albert’s home. The SUV’s taillight was broken, Lally has said, and pieces of it were later found outside Albert’s home.

Forensic testing showed that O’Keefe’s hair was on the vehicle’s bumper and his DNA was on the taillight, Lally said.

Lally also pointed to Read’s own comments — “I hit him” — that emergency personnel recalled her saying on the morning of Jan. 29.

Read says she was set up

Read has denied striking O’Keefe, and her lawyers have said she dropped him off and he went inside Albert’s home.

Read later realized that her boyfriend never came home, her defense team has said. Hours after Read said she dropped him off, she went to look for him with two other women and found him in Albert’s front yard.

Read’s defense lawyers have challenged key pieces of the prosecution’s physical evidence, including the broken taillight. Citing home security video that showed Read backing into O’Keefe’s car as she left to search for him on the morning of Jan. 29 and discrepancies in Proctor’s police reports, they suggested the pieces of taillight found outside Albert’s home could have been planted. (Proctor testified that the discrepancy was a typo.)

And the defense team has said that Read’s comments from the morning of Jan. 29 were twisted from a panicked question — “Could I have hit him?” — into a statement.

Medwed, the Northeastern professor, said that how those comments were used may show confirmation bias among authorities.

“She’s upset, she’s speculating,” he said. “She can’t remember what happened because she was so inebriated and maybe she’s thinking she hit him.”

“If you think Karen Read is guilty, then all of these factoids would support that theory,” he added.

Read’s lawyers, who were permitted to present an alternative theory of O’Keefe’s killing at trial, argued that O’Keefe may have gotten into a fatal scuffle at the party with another law enforcement officer — an agent with the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives whom Read had traded flirtatious texts with, then “ghosted.”

The lawyers have alleged that those who attended the party then dumped O’Keefe’s body outside and framed Read to cover it up. She was “a convenient outsider” in law enforcement officials’ attempt to protect one of their own, her lawyers said.

Lally has dismissed that claim as “rampant speculation.”

Language, relationships under scrutiny

Proctor admitted during trial that he used slurs and offensive language to describe Read in text messages to family, friends and supervisors. During testimony, Proctor also acknowledged having undisclosed personal and professional ties to Albert, the former Boston sergeant who owned the home where O’Keefe was found.

He testified that his comments and relationships did not compromise the investigation.

Proctor testified that he had worked a cold case investigation with Albert’s brother, an officer with the Canton Police Department, and had gone out drinking with him. And Proctor’s sister was close friends with Albert’s sister-in-law. The investigator testified that he’d previously asked the sister-in-law to babysit his children.

During the investigation, Proctor testified, he interviewed the sister-in-law — who had been out drinking with O’Keefe and Read before the party — and admitted discussing that conversation with his sister. The sister-in-law later offered Proctor a thank-you gift via his sister “when this is all over,” according to text messages between the siblings that were presented as evidence in court.

In testimony, Proctor said he never asked for a gift or received one. He denied sharing progress of the homicide investigation with his sister and added that he’d only made her aware of “newsworthy stuff.”

Proctor shared details of the investigation with several high school friends. In a group chat on the night of Jan. 29, hours after O’Keefe was found dead, one of the friends wrote that the person who owned the house where O’Keefe’s body was discovered “will receive some s—.”

“Nope,” Proctor responded, referring to Albert. “Homeowner is a Boston cop, too.”

Proctor presents a serious problem for the state’s case, said Roemer, the former prosecutor turned defense attorney in Dallas.

“Everything about Trooper Proctor was a problem,” she said. “He shouldn’t have been involved in this case. He should have taken himself out because he knew people that were witnesses in this case.”

To avoid a potential conflict of interest, state police led the investigation into O’Keefe’s death. But Proctor damaged that effort by sharing details about the case with others, Roemer said.

“When you have somebody like Trooper Proctor going around telling everybody in town intimate details of the investigation, you’re compromising it,” Roemer said. “Even if there’s not a conspiracy, you’re compromising it. He does not know who these people are talking to. But what he does know is that the people that he’s talking to know the people that live inside of the house where this happened.”

Two early-morning calls

At trial, Proctor said he wasn’t aware of two phone calls between Albert and the ATF agent, Brian Higgins, that the defense described as “curious” and potentially significant. The calls were made at 2:22 a.m. on Jan. 29, roughly four hours before O’Keefe was found dead.

Higgins said he had no recollection of the calls. Albert said a one-second call from his phone to Higgins was accidental. He said he didn’t answer a return call moments later that lasted 22 seconds. Proctor said he wasn’t aware of the calls because investigators don’t typically seize witnesses’ phones.

In the chat with his friends, Proctor said that Read, whom he called a “whack job” and identified using a slur, had “waffled” O’Keefe, or hit him with her SUV. He added that there would be “serious charges” brought against her.

Asked at trial if he’d wrapped up the case before fully investigating it, Proctor responded that in those early hours he’d already developed compelling evidence showing Read had struck O’Keefe with her vehicle.

Medwed said the revelations about Proctor’s investigation showed what he’s often seen in wrongful convictions — a tendency among investigators to develop “tunnel vision,” or a resistance to pursuing possible evidence or information that doesn’t fit their theory of what happened.

“The way that we see the evidence is tinged by our expectations and our theory of the case,” he said. “It seems as if the police did develop a theory pretty early that Karen Read committed the crime. As the case evolved, there might have been other avenues of investigation that they didn’t pursue.”

This article was originally published on NBCNews.com