Betty Hill has kept an eye on her front door for a heartbreaking 39 years, praying her daughter will open it and step back into her life.
But for all those years, Mrs Hill’s door has remained closed.
On Ballarat Cup Day, November 22, 1973, Sherrlynn Leigh Mitchell, 16, left her Eyre Street home to meet a friend at a bus stop. When the bus arrived, Sherrlynn was not there to meet it.
She didn’t go back to work at Ballarat Woollen Mills or collect her wages and holiday pay.
Her devastated family has not seen or heard from her since.
Mrs Hill, 81, maintains a constant vigil for her daughter from her Wendouree home and says the passing of time hasn’t made her pain disappear.
“It never gets easier, it’s really hard all the time,” she said.
“It feels like it was just yesterday . . . you always get that feeling that she could walk in the front door.”
Mrs Hill, who lost a second daughter in a car accident a few years later, said she had not given up on one day reuniting with Sherrlynn.
She said the formation of a new police unit dedicated to missing persons gave her hope of one day hearing news of her daughter.
“It’s good news, it’s just that it will bring up the worry all over again,” she said.
“It brings up a lot of pain, but it would be lovely if they found something.”
Mrs Hill said she hadn’t heard from police since the previous missing persons unit, the Belier taskforce, was disbanded in 2010.
She said she hoped the new team could help put her mind at ease.
“Sometimes I think she went away of her own accord, other times I think she would have told me she was going,” she said.
Sherrlynn’s brother Gerard Mitchell said he was happy with the new missing person’s unit.
“That’s great,” he said. “I got upset when the old taskforce closed,” he said.
Mr Mitchell said while many theories existed about his sister’s mysterious disappearance, the family had never given up hope.
Investigators refuse to give up hope
Detective Sergeant Dave Butler has made a career solving cold cases.
He has spent time during the past two years investigating one of Ballarat's biggest mysteries: what happened to Sherrlynn Mitchell?
The teenager vanished on November 22, 1973. Her family, friends and work colleagues never saw her again.
To coincide with National Missing Persons Week, Victoria Police yesterday launched a dedicated Missing Persons Unit within the Homicide Squad.
Unit member Detective Sergeant Butler said there was still hope for the Ballarat family.
He was assigned the Mitchell case after an inquiry from the US about two years ago.
"They had a Jane Doe in the US they thought may have matched Sherrlynn," he said.
"From Interpol we were able to obtain a copy of the DNA profile and to compare that with the DNA we obtained from her mother."
Sherrlynn was not a match, but with her DNA now in the database, new technologies evolving and an ongoing review process, Detective Sergeant Butler says investigators always hold out hope.
"We have a never give up attitude with missing persons," he said.
"You can't just give up, because history tells us there are times when we're able to solve cases years after the event."
Detective Sergeant Butler said computerisation and the creation of greater national links were big game changers.
For the investigators that live these cases, these things represent hope.
"These cases break your heart," Detective Sergeant Butler said.
"With a case like this, where the family has been tortured over years about what may have happened to her, of course we'd like to give them an answer.
"We keep our eyes on anything that might be new and emerging with science and technology to help us. We live it as well."
In Australia a person is reported missing every 18 minutes, with Victoria Police investigating about 6000 missing person cases annually.
Each year only a few of those people remain missing. They eventually join the long-term missing persons list and these are the cases that will be the focus of the new unit.
To report someone missing, contact your local police. If it is an emergency situation, such as a child or elderly person who has gone missing, call 000 for assistance. If you know the whereabouts of a person who has been reported missing or have information about a missing person, call Crime Stoppers on 1800 333 000.

