At 12:30 a.m. on January 7, 1969, Jane Britton (born May 17, 1945),[1] a graduate student in Near Eastern archaeology at Harvard University, left a neighbor's apartment in Cambridge, Massachusetts, United States, to return to her own.

Cambridge police and the Middlesex County district attorney's office announced in November 2018, two months before the crime's 50th anniversary, that they had identified a suspect in the case through DNA: Michael Sumpter, who had died in 2001 after being paroled into hospice care from a prison sentence that he was serving for a 1975 rape.

[9] The Harvard Crimson reported that the "littered and dingy" building had no locks on the outside doors despite repeated pleas from tenants to install them, along with a buzzer system, to further restrict entry to their guests.

Britton's own apartment door had a lock so dysfunctional she rarely used it; the Mitchells said she intended to move out of the building early the next year.

[10] Friends of Britton recalled that while an undergraduate at Radcliffe she had fought off an attacker on the Commons with a penknife, slashing his clothes in the process; the incident had not been reported to the police.

[11] On the night of January 6, 1969, the first Monday of the new year and the day classes resumed after the holiday break, Britton and Humphries joined other anthropology classmates for dinner at a local restaurant, after which the couple went ice skating on the Common.

She was officially pronounced dead by the medical examiner; by that evening he had performed an autopsy and, having found multiple lacerations to the head with underlying skull fractures, as well as a bruise on her arm, ruled the death a homicide by blunt force trauma that had occurred roughly 10 hours before the body was discovered.

[2] Another neighbor of Britton's told police that he had seen a man whom he described as about 6 feet (180 cm) tall and 170 pounds (77 kg) running away from the building at 1:30 a.m.[1] Because of the Harvard and Radcliffe connections, the case attracted national media attention.

Britton's body, along with the floor, walls, and ceiling, had been sprinkled with a reddish-brown powder identified as either red ochre or iron oxide.

[14] When police had told Professor Williams of this while discussing the case with him, he said that ancient Iranians, along with many other cultures in the world, had sprinkled it over the dead as a funeral rite.

Along with the way Britton's clothing had been used to cover her body, and the killer's apparent lack of interest in taking her valuables, that led to speculation that she had been killed by someone who knew her from Harvard and not a stranger.

[11] Nevertheless, Williams gave police a list of one hundred students and faculty from the department who might have had this knowledge, most of whom testified at a February grand jury hearing, expedited since many of them were due to leave the country for digs in a few months.

But at the same time he dismissed rumors that there had been friction among the team members in Iran that might have motivated someone to murder, saying nothing more serious occurred than the sort of minor tensions that arise among a group living and working closely together for an extended period.

She, too, was found by someone who had noticed her absence, in her case her employer since she had failed to show up for work, who entered the apartment with the assistance of the building's janitor.

[12] After the initial investigation and its frustrations, no further information of value emerged, and the now-cold case fell from the attention of the police, media and public as newer crimes took its place.

In the early 2010s, several writers—Widmer, New Yorker staff writer Becky Cooper, and Alyssa Bertetto, moderator of the Unresolved Mysteries subreddit—began looking into the case and requesting copies of the investigatory records.

Widmer observed that this was a common pattern for law enforcement in Massachusetts, to refuse to release all but the most basic information about long-cold cases.

Entered into the federal Combined DNA Index System (CODIS), that string came back as a "soft hit" on an identifiable suspect: Michael Sumpter, a convicted rapist who had died in 2001, a little over a year[18] after he was paroled from his sentence for that crime into hospice care for the terminal cancer from which he was suffering.

Researching the family on Ancestry.com[18] led police to him, and he provided them with a sample that matched the one believed to be his brother's closely enough to eliminate all but 0.08% of the human male population as suspects.

Two years before the killing, he had worked on Arrow Street about 1 mile (1.6 km) from the apartment, and at the time his girlfriend lived in Cambridge.

[1] At a November 2018 news conference, Middlesex County District Attorney Marian T. Ryan announced the results of the investigation: "Michael Sumpter ... has been identified as the person responsible for the 1969 murder of Jane Britton."

Although Sumpter could not be tried due to his death, Ryan stated that "I am confident that the mystery of who killed Jane Britton has finally been solved and this case is officially closed.

As one of the witness accounts at the time had suggested, despite the building's deficient security he had probably used the fire escape to gain access to Britton's apartment.

Toxicology reports from the autopsy had found that while Britton's blood was alcohol-free, her stomach had an 0.08% alcohol content from the Mitchells' sherry, suggesting that she had died before it could be metabolized, within a short time of returning to her apartment.

His height and weight at that time—5 feet 11 inches (180 cm) and 185 pounds (84 kg)—were close to that estimated by the neighbor who had seen the man running away at 1:30 a.m.[1] Despite the great significance originally accorded the scattered red ochre, police later concluded that it was a "red herring",[1] just flakes or other residue from Britton's painting, as it is a common pigment in paints.