It was one of the most bizarre abduction cases seen in recent years.
A young mum from northern California was out jogging in her quiet small town, when suddenly she vanished without a trace — only to re-emerge three weeks later on the side of a highway, battered, bruised and half-starved.
Two years on, we still don't know exactly who was responsible for her abduction, or why they chose to kidnap her, reports news.com.au.
But a number of inconsistencies in her story led some to believe it was all an elaborate hoax.
WHAT HAPPENED TO SHERRI PAPINI?
Sherri Papini was kidnapped while jogging out near her home in the small town of Redding in northern California on November 2.
That night, the then 34-year-old's distressed husband Keith Papini told the operator he came home from work to find his wife and children were not in the house. She was supposed to pick up their children from daycare, but never showed.
Mr Papini told the dispatcher he used an iPhone locator app to track her down, only to find her phone discarded near a dirt trail at Mountain Gate, near their home, along with a pair of headphones.
"I just drove down there, and I found her phone with her headphones because she started running again, and I found her phone and it's got her hair ripped out of it, like in the headphones," he said, breathing heavily.
"I'm totally freaking out, thinking that somebody, like, grabbed her."
Ms Papini was found beaten, badly-bruised and starved on the side of a highway in Yolo County — more than 200km from where she was last seen — in the early hours of Thanksgiving Day.
Her long blonde hair had been cut to shoulder length, and a branded message — of which police never revealed the details — was stamped into her right shoulder.
She was emaciated and weighed only 39kg, and had a quarter-inch-thick chain around her waist and host clamps on her wrists.
She was "battered and she had bruises in various stages of healing indicating she had been physically assaulted multiple times over a period of time," according to a police news release.
The petite blonde told police she had endured repeated abuse at the hands of two Hispanic women during her 22 days in captivity.
She told detectives that just before her release, she heard her captors arguing, followed by the sound of a gunshot. The younger attacker then took her from the room where she was held captive and dropped her off near the roadside where she was found.
But certain things in her story didn't add up.
MYSTERY DNA CASTS DOUBT ON PAPINI'S STORY
When detectives investigated Ms Papini's abduction case, they found DNA from two people — a man and a woman — during analysis of the clothes she was wearing.
It contradicts a central aspect of the California mother's story: that she was kidnapped by two Hispanic women.
Ms Papini has been unable or unwilling to provide a detailed description of her attackers, making it impossible for police artists to render composite sketches and fuelling speculation of a hoax.
She claimed she never got a good look at the women because they kept their faces covered — or covered hers — for most of the time.
The best description she could give of them was that one was between 20 and 30 years old, and had long curly hair, pierced ears, thin eyebrows and a thick Spanish accent, while the other was between 40 and 50 years old, with thick eyebrows and straight black hair with some grey.
She said they were driving a dark-coloured SUV with a "large rear-side window" when she was abducted.
The male DNA did not match that of her husband, Keith, who has since been ruled out as a
suspect and has passed at least two voluntary lie detector tests.
Authorities also revealed the existence of a male acquaintance from Michigan whom Ms Papini had been messaging and was planning to meet. It was not specified whether the texts were romantic or not, but police later said he was not involved in the incident.
The female DNA sample was taken from Ms Papini's body at the hospital. It did not match her own.
Both samples were uploaded into the CODIS DNA database, but to date there have been no matches to known offenders.
In October last year, Shasta County Sheriff's Office Sergeant Brian Jackson told People Magazine the alleged abductors gave her clothing to wear.
He said it was possible "that the clothing that was provided to Sherri are clothes that belonged to somebody who was an acquaintance of the captors, and hopefully down the road, once we get these females identified, we will get the answers for that".
PAPINI CLAIMED TO HAVE CUT HER FOOT
The gender of Ms Papini's alleged abductors wasn't the only inconsistency in her story.
The California woman also told investigators she got into an altercation with the younger abductor in the bathroom when she was allowed to shower.
"During that altercation, she reported she slammed the captor's head into the toilet in the bathroom before she was subdued and returned to her room where she was held," police said. "She reported she had cut the side of her foot during the confrontation. However, when photographs of Sherri were being reviewed at the hospital, there is no evidence of the cuts seen in the photographs."
Authorities noted it was "obviously an inconsistency", but said stressful circumstances can often affect a victim's memory.
Other experts have pointed out how rare it is for abductors to get away with their crime and not attempt to repeat it.
Ken Ryan, a law enforcement expert from California State University, told Newsweek he believed the story was most likely false.
"In my 25 years I've never seen a case like this where someone was kidnapped, held captive for 20 something days then just released," he said. "None of it makes sense."
WHAT NEXT FOR THE PAPINI CASE?
As 2018 draws to a close, we still don't know exactly what happened to Ms Papini, or whether her alleged captors will ever be caught.
Late last year, a neighbour told Newsweek that the woman leads a "very quiet life" at home and rarely goes outside, trying to put her life back together after the ordeal.
"She doesn't come out of the house," neighbour Joyce Allison said. "I don't see the kids out playing in the yard. I honestly don't know if the story is true. If it is, I'm sure we'll find out. If it's fake, we'll find out soon enough."
Another neighbour — who requested anonymity — said they just wanted the family to find closure.
"I hope if her story is really true that she's getting along all right and getting counselling so she can live with it and get better," the neighbour said. "But, is it a real story? I don't know. I hope one day we'll all have the answers."
"It has taken time for Sherri to recover to a point to be able to provide accurate details to the sketch artist," the Shasta County Sheriff's Office noted in a news release last October.
Ultimately, Ms Papini now lives in secret. She's said to be afraid of the media, which continues to follow her for paparrazi shots.
While her long blonde hair has grown back and her bruises have been healed, the branding still remains on her skin as a crude reminder of what she went through. We may never know who was responsible.