Sandra Birchmore planned to announce her pregnancy on Valentine’s Day.

On February 1, 2021, as a blizzard swept through eastern Massachusetts, the 23-year-old holed up in her apartment in the Boston suburb of Canton. She was about 10 weeks pregnant and had shared the news with only a handful of people.

In two weeks, she intended to post a pink-and-blue poster on social media decorated with tiny footprints. “I’m expecting a new little one to love,” it read. “My own little Valentine arriving September 2021.”

With snow piling up outside, Birchmore stayed mostly indoors and prepared for motherhood. She texted a friend about newborn clothes, searched for nursery furniture and chose a maternity photographer. At 5:33 p.m., a surveillance camera captured video of her stepping outside to retrieve a windshield snow brush in turquoise leggings and a dark puffy jacket, her hair piled into a high bun.

They are the last known images of her alive.

Police found her body three days later in a seated position on her bedroom floor. A duffel bag strap was looped around her neck and tied to a closet door handle. Her phone lay inches from her body and had locked at 9:13 p.m. on February 1, federal investigators said.

The Massachusetts Office of the Chief Medical Examiner ruled her death a suicide. But to her family, nothing about it made sense.

She wanted to be a mother. She’d already bought onesies. She was making plans. “That’s all she was talking about. I mean, really, really excited,” said her cousin, Angelique Pirozzi. “It was a goal of hers. She was glowing.”

Within days of Birchmore’s death, Pirozzi called local authorities and urged them to take a closer look into what happened inside her cousin’s apartment that wintry night.

“My message to the police was no one in Sandra’s life thinks she would kill herself,” she said. “Everyone seemed disinterested in entertaining the idea that this might not be a suicide.”

More than three years later, federal investigators stepped in. And in August 2024, a federal grand jury dropped a bombshell: Allegations that a police officer killed Birchmore to stop her from exposing a sexual relationship that started when she was 15.

The officer, Matthew Farwell, worked for the nearby Stoughton Police Department, and his wife was expecting their third child at the time. He believed Birchmore’s unborn child was his, but a DNA test after her death determined he was not the father, according to a federal affidavit.

Farwell has pleaded not guilty to killing a witness or victim and violating a federal law protecting unborn children. His attorneys declined to comment because the case is ongoing. He’s due back in court today for an evidentiary hearing, with a trial expected to begin in October.

Farwell’s attorneys have argued that Birchmore’s journals suggest she was considering suicide. But federal investigators said a broken flamingo charm necklace on Birchmore’s bedroom floor told a different story. So did surveillance video showing a masked, hooded figure entering her apartment building that night and leaving 29 minutes later, they said.

This account of Birchmore’s final day – and her tragic life – is based on court records and interviews with her family and law enforcement, as well as data recovered from her iPhone and laptop. They reveal a challenging childhood, an alleged illicit relationship with an adult mentor and a disputed cause of death that ultimately led the medical examiner to change the official ruling.

“What happened to Sandra Birchmore was a profound tragedy that should never have occurred,” said Stoughton Police Chief Donna McNamara. “She was a young woman who deserved to be protected, not exploited.”

Her mother thought she needed a male role model

Sandra Birchmore was largely raised by her mother, Denise Birchmore, who struggled with heart disease, emphysema and asthma. As an only child, Birchmore took on caregiving responsibilities at a young age and had to grow up fast, her cousin Pirozzi said.

Her mother and grandmother doted on her. During crowded family gatherings at her grandmother’s home, Sandra soaked up the noise and chaos, happy to have other kids around.

“She had these beautiful, bright blue eyes and these freckles across the bridge of her nose,” Pirozzi said. “She was excited and giggly and tickled to have all these guests in their house.”

With young Sandra’s father out of the picture, her mother wanted her to have positive male role models. In spring 2010, when Sandra was 12, her mother signed her up for the Stoughton Police Department’s explorers’ program – an initiative that exposes youth to law enforcement careers.

“It was supposed to be a positive thing … for kids who might need an additional role model in their life,” Pirozzi said.

Two years later, Matthew Farwell joined the Stoughton Police Department and became an instructor in the program.

By then, Sandra appeared to be thriving as a police explorer. She posted photos in her black uniform with a police explorer badge. In June 2013, she announced on Facebook that she’d achieved the rank of sergeant.

But by then, prosecutors said, Farwell was secretly grooming her. He gained the trust of the teen and her family by helping her with her homework, Pirozzi said.

Before long, he was meeting her in his patrol car or his truck to have sex, sometimes while he was on duty. Occasionally, she skipped class – and even her prom – to be with him, according to federal documents.

Federal court filings allege Farwell was sexually involved with Birchmore from the time she was 15 until her death at 23. In Massachusetts, the age of consent is 16. “Farwell used his authority and access to groom, sexually exploit, and ultimately sexually abuse then-15-year-old Birchmore … until he killed her,” investigators wrote.

Birchmore’s relatives knew Farwell had taken an interest in helping her with schoolwork. But not that things had turned sexual, Pirozzi said.

Other officers also abused her, a police chief says

Birchmore’s mother died after a stroke in May 2016. About a month later, her grandmother passed, suddenly leaving her without a support system.

She sunk into depression not long after, her family said.

By then, several other Stoughton Police officers were sexually involved with her, federal prosecutors said, including Farwell’s twin brother, William, who also worked for Stoughton Police.

William Farwell did not respond to CNN’s request for comment. But his attorney, David M. Bae, has denied that his client was having sex with Birchmore when she was underage.

“There has never been … a scintilla of evidence that my client had sexual relations with SB while she was a minor,” he said at a police misconduct hearing following the federal allegations.

Only Matthew Farwell has been criminally charged.

“Once they got their hooks in her,” Pirozzi said, “she didn’t have a chance.”

Stoughton Police Chief Donna McNamara ordered an internal affairs investigation after Birchmore’s death.

“The investigation revealed, starting when Sandra was a young teenager, a pattern of abuse and generally inappropriate and abhorrent behavior by multiple men who were, at different times, employed by the Stoughton Police Department,” McNamara told CNN in a statement.

Four officers, including the Farwell brothers, were decertified and are barred from working in law enforcement in the state.

In the months before Birchmore died, rumors about her relationship with Matthew Farwell had started leaking out.

As this happened, federal investigators believe Farwell became increasingly alarmed. In late January, a friend of Birchmore’s called the Stoughton Police Department and notified them of the sexual relationship with Farwell, according to federal documents.

Farwell was outraged when he found out. He sent Birchmore expletive-filled text messages, federal documents show.

“Dude, your f***ing friend called my job Sandra wtf,” one said.

She wanted a baby and gave him an ultimatum

Pirozzi said Birchmore’s loved ones warned her about Farwell.

“She was getting lots of advice from people telling her to be careful with this guy,” Pirozzi said. “But grooming doesn’t allow for those voices.”

Pirozzi was concerned about her young cousin taking on motherhood alone. One of Birchmore’s last messages to her was a Facebook inbox seeking stroller recommendations.

“I said to her, ‘I am happy that you’re happy, but you know there’s kind of larger issue here … You have to think long and hard about whether you’re ready to do this,’” Pirozzi said. “I was trying to encourage her to think about this choice. My thing was, ‘What stroller you should get? You’re asking the wrong questions.’”

Sandra Birchmore had planned to post this image online announcing her pregnancy.

At the time, Birchmore worked at a local elementary school as a teacher’s aide and had started taking classes to prepare for nursing school later that year, said Barb Wright, her mother’s cousin.

She was a young woman creating her own little family, and her life seemed to be coming together, Wright said.

But her relatives later learned that months earlier, in October, Birchmore had given Farwell an ultimatum: If he agreed to have unprotected sex to conceive a child, she would not disclose their relationship, according to her text messages cited in federal documents.

She knew having sex with a minor is a crime and threatened to disclose their relationship. A reluctant Farwell eventually agreed to try for a baby, prosecutors said, and she sent him her ovulation schedule. “The two started discussing timing their sexual encounters around specific times in Birchmore’s cycle,” the affidavit said.

In December, Birchmore texted Farwell that she was pregnant, and sent him a photo of a poster she’d made to celebrate. “Congrats, we are goin’ to be parents,” it read.

She also texted him a list of expectations. She wanted the child to have his last name. She also wanted him present for the birth and for a few days around Christmas and Easter, according to federal documents.

“I feel like I’m trying to be as fair as I can. And I want you there for (my) labor … That I’m standing my ground on,” she texted.

But prosecutors said Farwell appeared displeased about the baby. He told her, “That’s not my child,” when she showed him the sonogram, Birchmore told a friend, and shoved her, the affidavit said.

At times, Farwell asked her to delete their text conversations. In one exchange about the baby, he told Birchmore she was asking for more than she ever had before.

“And still less than what any other girl would ask for,” she texted back.

Text messages detail the arc of their relationship

Data from Birchmore’s iPhone and laptop helped federal investigators piece together key moments in her relationship with Matthew Farwell. Text messages created a detailed record of their communications and movements in the months, days and hours leading up to her death.

The digital trail dated back years. It showed Farwell sent her a Facebook friend request in October 2012, when he was 26, according to the federal affidavit.

Over the years, the pair made references to the beginning of their relationship, including messages from Birchmore about having “butterflies” the day he took her virginity when she was 15, according to the affidavit.

In late January – days after Birchmore’s friend called Farwell’s workplace – he asked for keys to her apartment and said he’d stop by for “hugs,” the affidavit said. During one of his last visits to her apartment, Birchmore texted a friend that she noticed him inspecting her closet and bathroom and she thought it was “really weird,” an affidavit said.

Investigators allege he was scouting the apartment for a place to stage her death.

At 9:08 p.m. on February 1, 2021, Farwell texted Birchmore and asked whether he could come over, the affidavit said. She told him she’d leave the door unlocked.

It was the final outgoing message on her phone. Farwell arrived four minutes later wearing a dark hoodie and a medical mask, the affidavit said.

Surveillance video shows him leaving her building at 9:43 p.m. — about half an hour after her iPhone locked and stopped recording movement.

Surveillance video shows this hooded, masked man entering Sandra Birchmore's apartment building the evening of February 1, 2021 — the last day she was seen alive. Prosecutors say it was Matthew Farwell. Farwell’s attorneys say he visited her apartment that evening but deny his involvement in her death.

The case follows another high-profile death in Canton

Birchmore’s body was found after she didn’t show up for her job at the elementary school and her co-workers requested a welfare check.

Pirozzi said she began raising alarms about Farwell with local and state police within days of learning about her death.

“It was really important for them (police) to understand that Sandra was in a long-term, intimate relationship with a married Stoughton police officer who was not happy about her pregnancy,” Pirozzi said. “It was very important that we created an environment where people couldn’t look away.”

But Farwell wasn’t arrested for three and a half years, leading to protests by local residents about lack of action by law enforcement. A spokesperson for the US Attorney’s Office in Boston declined to comment on what prompted the federal investigation or why it took that long.

A law enforcement source told CNN the delay in arresting Farwell points more to “shoddy police work” than any cover-up by local police. So far federal investigators have found no evidence of such a cover-up, the source said.

Birchmore died in Canton, a town facing intense scrutiny over how police handle high-profile death investigations.

Almost a year to the day after Birchmore’s death, Boston police officer John O’Keefe was found dead in the snow outside a Canton house party in January 2022. His girlfriend Karen Read was accused — and later acquitted — of murder after two trials that drew national publicity. Critics of that case said investigators ignored crucial evidence and made key errors, concerns echoed by Birchmore’s family.

Melissa "Mizzy" Berry speaks during a protest against law enforcement actions in cases involving Sandra Birchmore, Karen Read and others, outside the Norfolk District Attorney offices in Canton, Massachusetts, on November 13, 2024.

Canton Police Chief Michael K. Daniels, who took over the embattled department earlier this year, said local officers responded to Birchmore’s apartment alongside Massachusetts State Police and the District Attorney’s Office, while the Office of the Chief Medical Examiner ultimately determined the cause and manner of death.

“This was not a Canton Police-led investigation … we work in a support role. That structure is consistent with how investigations like this are handled in communities like ours, where those agencies have jurisdictional authority and specialized resources to lead,” Daniels told CNN via email. “Our role is to respond, secure the scene, gather information, and document initial observations. … Any preliminary information communicated early in an investigation should not be interpreted as a final determination.”

In court filings, federal prosecutors said the medical examiner did not send state pathologists to Birchmore’s apartment but relied on local authorities, who shared incomplete or inaccurate information. The Canton Police sent a single paragraph to the medical examiner “stating in a conclusory fashion that Birchmore’s death was a suicide by hanging,” federal documents said.

Daniels, the Canton police chief, told CNN he understands people want answers but declined to speculate on agencies’ past decisions or intent while the case remains active.

“My focus is on being as transparent as we can within the law and ensuring we meet community expectations,” he said.

The Massachusetts State Police referred questions about the Birchmore case to the Norfolk County District Attorney’s Office. A spokesperson for the DA told CNN via email that prosecutors spent significant time investigating Birchmore’s death alongside state partners and emphasized that the medical examiner’s office was responsible for determining the official cause of death.

The medical examiner’s office said its initial findings were based on the information available at the time. It declined to comment further, citing the ongoing criminal case.

Stoughton Police Chief Donna McNamara addresses the media in August 2024 after charges were announced against former officer Matthew Farwell.

In an unusual move, the agency last month updated Birchmore’s death certificate from its original finding of suicide. It now lists asphyxia as the cause of death and the manner as “undetermined.”

McNamara, the Stoughton Police Chief, told CNN her department focused on determining whether officers violated policies in their interactions with her. She turned over her findings to state and federal investigators.

The fallout from the case has led to demands for change and accountability. Following a vote by Canton residents, a 2025 independent audit recommended sweeping reforms for the town’s police department, including expanded training and mandatory reviews of all death investigations by supervisory staff.

Daniels said the department is working through those recommendations as part of a broader effort to rebuild public trust.

Farwell’s attorneys argue Birchmore was suicidal

Farwell, 40, has been in jail since his arrest in August 2024.

His attorneys sought his release on bail after DNA ruled him out as the father of Birchmore’s unborn baby. Investigators have not revealed who the father is. But prosecutors have said Farwell believed the child was his at the time of Birchmore’s death.

“It is the fact that Farwell held this belief — and not the fact that he was mistaken — that will be most relevant at trial,” prosecutors wrote in an April 2026 memo against Farwell’s release on bail.

In the same memo, prosecutors said Farwell’s DNA was found in Birchmore’s underwear and on the duffel bag strap around her neck.

However, Farwell’s attorneys have argued that his was one of four DNA profiles found in her apartment, on the underwear and on the strap.

“Complex mixtures cannot be claimed to match any given individual,” his attorney Joanne Daley told the court at his detention hearing.

Farwell’s attorneys have argued in court filings that Birchmore was suicidal and had a history of mental health issues dating back 14 years. But prosecutors said they spoke with her relatives, friends and therapist, who all agreed she was not suicidal.

“Birchmore spent parts of her life depressed and anxious. That is no secret. And perhaps that’s in part because she’d been … exploited by a local police officer since her childhood, forced to act out rape fantasies,” federal prosecutors wrote in court documents. “Depression and anxiety do not equal suicidal ideations.”

Wright, her mother’s cousin, said Birchmore struggled with the loss of the matriarchs in her family but was not suicidal.

On February 1, 2021 – the day she died, Birchmore Googled, “What color is the suicide ribbon?” The defense has said this is evidence she contemplated suicide, but the prosecutor said she was just curious after seeing similar ribbons on social media.

In her journal, she’d listed ways to commit suicide, including using a rope, the defense said.

At his bail hearing, Farwell’s attorneys said he does not deny going to her apartment that evening. “He was there that day. They had an argument, that he ended things with her, told her he was not the father, and he left,” Daley told the court.

Prosecutors have disputed that narrative in their affidavit.

“Once inside, he killed her and staged her body and apartment to make it appear that Birchmore had died by suicide,” they said.

Prosecutors say her broken necklace and scattered hairpins from her updo point to a struggle. But the defense has challenged that interpretation, arguing that Farwell’s DNA was not found under Birchmore’s fingernails.

Protesters are following the case closely

At the bail hearing last month, prosecutors and defense attorneys offered starkly different portraits of Farwell.

The defense described him as a decorated US Army veteran who served in Afghanistan and earned medals as a police officer for saving lives. But federal prosecutors called Farwell a “dangerous” man and warned he would do whatever it took to avoid a mandatory life sentence.

Outside the federal courthouse in Boston, a small group of protesters has gathered during many of Farwell’s legal proceedings — much like they did at hearings for Karen Read. They held blue signs that read, “Justice for Sandra Birchmore” alongside a large photo of her face.

Barb Wright, right, attends a rally for her cousin Sandra Birchmore on October 19, 2024, in Stoughton, Massachusetts.

Supporter Melissa Berry told CNN she started following the case in September 2022, when Police Chief McNamara released the internal report on the Stoughton Police officers who were sexually involved with Birchmore.

“I was in my room folding clothes … and this news report comes on and … I’m screaming at my TV, like what? How does this happen in a police department?” Berry said.

Soon after, Berry was driving from her suburban Boston home to protest outside the federal court during Farwell’s hearings. With Birchmore’s family’s permission, she started a Facebook group, “Justice for Sandra Birchmore,” which has about 20,000 supporters who share information and discuss evidence.

Berry said she thinks about Birchmore’s mother and how she believed she was doing what was best for her daughter, not realizing the devastating impact the police explorers’ program would have on her life. One question keeps replaying in her mind: “Who do you go to when the police are abusing you?” she said.

On May 13, Berry and other protesters gathered in Stoughton to mark what would have been Birchmore’s 29th birthday.

Meanwhile, for Birchmore’s family, the emotional toll persists. Last month the medical examiner notified them of the change to the death certificate, Wright said. She’s relieved it no longer states her second cousin died by suicide.

After years of waiting and with the federal prosecution underway, Birchmore’s relatives believe justice is within reach.

“Everyone’s kind of holding their breath,” Pirozzi said.

Birchmore had also planned to reveal her baby’s gender on Valentine’s Day, the affidavit shows. She was expecting a boy. (CNN)