Sherri Papini's schoolfriend Tera Smith vanished from same road 18 years ago

The case of a missing teenager, Tera Smith, from 1998 has been linked to Sherri Papini's abduction. Photos / Supplied, Facebook

With their blue eyes, long blonde hair and willowy build, Sherri Papini and Tera Smith could have passed for sisters.

Tera was a 16-year-old Central Valley High School homecoming princess when she went missing on August 22, 1998 in a case which has chilling parallels to Mrs Papini's abduction.

Like Mrs Papini, Tera vanished while jogging along the Old Oregon Trail. Unlike Mrs Papini, who was miraculously released after 22 days by her alleged kidnappers on Thanksgiving morning, Tera was never found.

Sunrise Drive, the last known location Sherri Papini before she was abducted. Photo / AP

Tera's fate has always haunted her fellow schoolmates - including Mrs Papini (then known as Sherri Graeff) and her husband Keith, who were in the year above Tera at Central Valley but knew her well.

After Mrs Papini disappeared on November 2, residents of rural Redding in northern California immediately questioned whether the case could be linked to Tera's.

"They look similar and the circumstances are very similar. That was the last one people were scared over," said Lianne Bowman, the owner of a dog-grooming business a short drive from where Mrs Papini's iPhone was recovered.

The chilling parallels prompted Keith Papini to reach out to Tera's father, Terry Smith, in the first few days of Sherri's disappearance.

But it wasn't just to ask for advice - it was to raise the possibility that the person who took Tera all those years ago and got away with it may have struck again.

The 16-year-old is widely believed to have been murdered by her martial arts instructor Troy Zink, with whom she had been having a relationship with.

Mr Zink, then a 29-year-old married father with a young son, was the last person to see Tera alive.

Tera was last seen wearing a sports top, shorts and tennis shoes and may have been seen with a white male companion who may have been her karate instructor. Photo / missingkids.com

He told authorities that Tera called him during the evening hours of August 22 and asked him to meet her near her home at 6:30pm.

Mr Zink claimed that Tera requested $US2000 from him during the meeting and became angry when he refused.

He told police that Tera asked him to drop her off at the intersection of Old Alturas Road and Old Oregon Trail in Redding. He claimed he then drove to Hang Glider Hill, alone, to "pray", returning home about 11.30pm.

Despite having been named as the prime suspect in Tera's disappearance and suspected murder, a lack of evidence - including a body - has meant that Mr Zink, now 49, was never charged.

"At least in our case we had a suspect - somebody we think was responsible for it," Mr Smith told The Sacramento Bee of his meeting with Mr Papini.

"In many ways it's worse than what we had to go through because at least we pretty much knew who did it, and what he did, and even though we never found her body, we've kind of come to terms with that.

"In the Papini case, they've got nothing. Nothing at all. I didn't have a lot of comfort to offer him. I'm not real confident that anything's going to come out of it, but how do you tell somebody five days after their wife's gone missing that she's probably gone for good?"

Mrs Papini's sister Christine Koester, who also knew Tera at school, said the teen's disappearance had also been on her mind.

Sherri Papini with her husband Keith and their two young children. Photo / Facebook

"For them to be so closely related in that we all went to high school with them, and they look like each other, it's all very strange," she told the Bee on November 11 while her sister was still missing.

"We feel that she's going to walk through the door at any time."

Incredibly, Mrs Papini did "walk through the door again", released after 22 days in captivity and bondage, during which time she was beaten, starved and even branded by her abductors, who remain unidentified.

Convinced of a link between the two cases, online sleuths have been trying to track down Mr Zink, who is believed to have started a new life in Hawaii after leaving his home in Anderson, near Redding, several years ago after numerous run-ins with the law.

After Tera vanished, Mr Zink was convicted of weapons charges and sentenced to four years in jail. In 1993, he was jailed for another year following a rape conviction.

Despite his affair with the underage girl and a proven propensity for violence, Mr Zink has always denied doing anything to harm Tera.

Sheriff Tom Bosenko addresses the media during a press conference regarding former missing woman Sherri Papini who was found. Photo / AP

He told authorities the teen had outlined her plans to run away in a letter she wrote to him weeks before she vanished.

Tera's family has maintained that while she was a typical teenager going through some problems at the time, those problems were not serious enough to cause her to leave forever.

Her parents only discovered Tera and Mr Zink's affair after going through her journal for clues.

They found several entries referring to her decision to end their relationship in the days before she vanished. The Smiths believe that on the last day she was seen, Tera contacted Mr Zink and tried to break it off with him.

After his 1998 initial police interview, Mr Zink refused to co-operate any further with authorities.

Shasta County Sheriff Tom Bosenko, who worked on Tera's case and still keeps a photo of the teen on his desk, has acknowledged the similarities between the Smith and Papini cases are unnerving.

"Sherri is 34 years old, but she looks much younger," Mr Bosenko said when quizzed by reporters earlier this month about a possible link between the cases.

"They could probably pass for sisters."

Despite this, it was unlikely the two cases were related, he said.

Investigators are still trying to work out who kidnapped Mrs Papini and why. She has described her captors as two Hispanic women armed with a handgun.

Meanwhile, the Papinis have apparently skipped town.