It looked like an overdose, with pills scattered all over the bedroom floor. But she had been strangled.

Her boyfriend, Brian J. Bowler, told police that when he found her lying on the floor, she wasn’t breathing. She had been dead for at least four hours, someone from the state medical examiner’s office determined. At 3:30 a.m., her body was removed from her home and police cleared the scene.

But after an autopsy was performed on Martini’s body, the state medical examiner’s office called Martini’s family with jarring news: Marcie had not overdosed. The toxicology report showed normal levels of her prescribed medication, but no evidence of alcohol or any other drug in her system. The actual cause of her death was blunt force trauma to the neck; she had been strangled.

Suddenly, the Walpole Police Department had a homicide case on its hands. Investigators returned to the neighborhood to interview people and try to figure out who killed her.

Martini was a relative newcomer to Walpole. She had spent most of her life in the suburbs west of Boston, graduating from Lincoln-Sudbury Regional High School in 1981 and later attending Regis College in Weston. She moved to Walpole in 1993 as a newlywed. She and her husband, Robert Martini, settled into a townhouse on Teal Circle, a cul-de-sac in a quiet residential community called Swan Pond. But their marriage didn’t last. Robert eventually moved out, while she continued to live in the condo with her dog, Rocky.

The first half of 1996 had been tumultuous for Martini. She had been dating Bowler but by March their relationship had deteriorated so much that she took out a restraining order against him.

At one time, Bowler and Martini had worked at the same office, at Executone in Westwood. By the summer of 1996, Martini had quit that job and began looking for a new one.

According to her family, Martini wanted to move on and had packed up Bowler’s belongings in garbage bags.

In a 2008 interview with the Globe about the status of the investigation, Walpole Police Detective Jim O’Connell noted that several bags filled with Bowler’s clothes were found at Martini’s condo and it appeared that Bowler had been staying in a guest bedroom.

During the investigation, police questioned several men who had relationships with Martini, but none was ever named as a suspect. Martini’s estranged husband, Robert Martini, was out of state on July 10, and witnesses corroborated his whereabouts.

Bowler told police that on the night of Martini’s death, he had worked late and gone to a Chinese restaurant in Norwood before stopping by the Rebel Restaurant in Walpole. When he got back to the condominium, he found Martini’s body.

Police checked out Bowler’s story and corroborated his account with witnesses, O’Connell said.

Although he had an alibi and was never charged in connection to Martini’s death, Bowler said many people suspected he was involved.

“There were so many false accusations said against me,” Bowler said in a phone interview. “It was hurtful to me and my family.”

All these years later, Bowler vividly recalls what he saw at the condo that night.

“There were pills all over the place,” Bowler said. “Way back then, I spoke my mind about it ... if they really wanted to say someone hurt Marcie, then I can tell you goddamn it wasn’t me. Because I would never hurt anybody that I cared about, ever.”

In a 2004 interview with WFXT-TV, O’Connell said he believed that whoever killed Martini made it look as if she had overdosed by scattering her pills on the floor.

O’Connell noted there was no sign of forced entry or a struggle and there were no reports of Martini’s dog barking on the night of her death.

“It was someone she knew,” O’Connell told the Globe in 2008. He described the case as “extremely frustrating.”

The lack of physical evidence and eyewitness testimony “kept us going in circles,” he said.

In 2005, Martini’s body was exhumed in an effort to find new DNA evidence. Authorities removed her fingernails in the hopes they contained evidence from fighting off her attacker. They were sent to a laboratory for testing but the results came back as inconclusive.

Martini’s family had long wanted to know whether any forensic evidence was saved from her autopsy, hoping it could yield a DNA sample.

Martini had always worn her nails long, but at her wake her mother noticed that her nails had been cut short.

In a 2012 letter to the Norfolk District Attorney’s office, Martini’s mother, Connie Fusillo, asked about her daughter’s fingernails and other samples that may have been taken from her body and clothing.

“I do not know if the samples were tested or mishandled or if they even exist today,” she wrote. “On Page 3 of the autopsy report the nails are described as long and intact. At her wake I observed them, on the contrary, as cut short and rough, perhaps with a serrated implement.”

Martini’s younger brother, James J. Fusillo, said a prosecutor in the Norfolk District Attorney’s office once told his family that her fingernails had been cut and the clippings had been lost. But a state trooper later told them the prosecutor must have been mistaken.

Could advancements in DNA technology help solve this case?

James Fusillo hopes so, because he would like his sister’s killer to be brought to justice.

“It’s too bad my father, who passed away in 2013, and my mother, suffering from old-age health issues, will never have the opportunity to find out who killed their daughter and why that person has never been held accountable for his crime,” he said. “I’m hoping someday I may know.”

Anyone with information regarding this case is asked to contact the State Police Detective unit at the Norfolk District Attorney’s office at 781-830-4990.

Emily Sweeney can be reached at emily.sweeney@globe.com. Follow her @emilysweeney and on Instagram @emilysweeney22.