"It was personal," says Los Angeles Police Department cold case detective Luis Rivera. "It was a maniac…or love gone wrong."
The timing and the MO of the murder – just three months earlier actress Sharon Tate and several others had been viciously stabbed to death by the Manson Family a few miles away – fueled speculation that the victim could be connected to Charles Manson and his followers.
A caretaker at Spahn Ranch, the notorious Manson Family hangout, told police that the young woman looked like a hippie named Sherry from Simi Valley who spent time at the ranch.
But police were unable to identify the woman, who became known as Jane Doe #59, and her identity remained a mystery for 46 years.
Now, police know who she is and are working to determine who killed her.
CSU Archives / Everett
Ralph Crane / The LIFE Picture Collection / Getty
PEOPLE exclusively reveals in this week's issue that Jane Doe #59 is Reet Jurvetson, who was born in Sweden, grew up in Montreal and was 19 when she died.
"Manson claims there are other victims," says retired LAPD detective Cliff Shepard who reopened the case in 2003. "She could have been someone who was at Spahn Ranch."
Want to keep up with the latest crime coverage? Click here to get breaking crime news, ongoing trial coverage and details of intriguing unsolved cases in the True Crime Newsletter.
In October, Rivera and his partner, detective Veronica Conrado, interviewed Charles Manson at Corcoran State Prison to see whether he recognized the dead woman. "No new leads were learned," he says. But, he adds, "We can't rule out that the Manson Family was involved."
The break in the case came last June when a friend of Reet searching crime websites saw her post-mortem photograph and called Reet's sister, who then contacted law enforcement. DNA taken from Jane Doe #59's bloody bra matched her sister.
For much more on Jane Doe #59 and the search for other possible victims of the notorious Manson Family, pickup this week's issue of PEOPLE, on newsstands Friday
Police learned that Reet flew to L.A. in the summer of 1969 to visit a man named John, or Jean, with the French pronunciation, she met in a Canadian coffee shop. "She was smitten by him," says Rivera. After she arrived, she sent her family a postcard to let them know she was happy, and had a nice apartment.
"In 1969 there was a lot of peace, love and flower children," says Shepard. "L.A. was the place to go for young people."
But, after the postcard, her family never heard from her again.
"As incredible as it seems, my parents never thought to report Reet missing to the police," her sister Anne wrote in a family statement. "They thought that she was just living her life somewhere and that eventually news from her would turn up."
Anne described her sister as "free-spirited and happy," with a "taste for adventure and freedom."
"Although our family continuously hoped that one day Reet would return home, I eventually came to the conclusion that she had probably passed away," Anne wrote.
"It is such a sad, helpless kind of feeling to always question, to never know.... After all these years, we are faced with hard facts. My little sister was savagely killed. It was not what I wanted to hear."
Rivera says he is determined to solve Reet's murder, and identify the mysterious man named John, or Jean.
"He is the best lead we have," he says, adding: "No one deserves what happened to her. Someone might be out there who is responsible and it is our job to find out who it is and bring them to justice if we can."