A 50-year-old mum who was probably the last person to see Leah Croucher before she disappeared has spoken out about how the teenager seemed "perfectly normal and calm" on that fateful morning.
And she says she feels puzzled and let down by police, claiming they took two years to acknowledge that her sighting could be genuine. Although in response police insist she was 'taken very seriously from the outset'.
"It just makes me wonder if anything has been missed or if anyone else saw something that could be important and police didn't seem to take much notice," the witness said.
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Crucially, the witness appears to be the only person to have seen Leah's expression and demeanour on the morning she vanished. This alone could provide a vital clue in the mystery about whether she was abducted, vanished of her own free will or even took her own life.
Every morning for six months, from September 2018, the mum had walked her children from her Furzton home to their school in Bletchley. And every weekday morning she smiled or nodded a greeting to the pretty, fresh-faced teenager who was making her way to work.
"It was always at the same time, between 8.15am and 8.20am, and always in the same place on Furzton. We'd pass on the pavement and be literally inches away from each other.
"She was about the same age as my daughter. I always thought she looked such a nice girl. It got to the stage where we'd acknowledge each other with a nod or smile, as you do when you see someone so frequently."
On the morning of February 15 2019, the mum saw 19-year-old Leah as she was walking past TellyTubby Hill, a mound of earth opposite the Tesco Express store and Merebrook Infants School.
"She nodded hello to me and I smiled back. She looked exactly the same as she always did. As usual, she wasn't wearing make up and she was walking like she always did, with her hands in her pockets.
"She didn't seem in a hurry, she didn't seem agitated and she didn't seem upset in any way or like anybody planning to do something out of the ordinary. She didn't look excited, or scared or anything. She was walking along, looking perfectly calm, as she'd been every morning for the past six months.
"It all seemed perfectly normal."
In fact, that morning had a far from normal outcome. Leah failed to show up at her workplace in Knowlhill and was reported missing the same day. Two years and seven months on, she has still not been found and police and her family have no clue as to what has happened to her.
The mum was horrified when she recognised the photos of the missing teenager and realised it was the girl she'd seen every morning.
"I swear she didn't look any different. If she'd have seemed upset about anything or scared or distressed then I would most definitely have stopped and asked if she was okay. I'm a mum and that's what I do."
The next week was half-term but afterwards, when school started again, the mum couldn't stop looking out for the girl at the spot they used to pass.
"I was hoping I'd been wrong, that it wasn't Leah and that the girl I'd seen and smiled to every day would still be there. But, of course, I never saw her again."
The mum says she reported what she'd seen to police. She says around three weeks later, two female detectives came to interview her.
"They really fired questions at me and I answered the best I could. I said she wasn't carrying anything because she had her hands in her pockets . She had her rucksack bag on her back as usual and she was wearing the same type of clothes she always did - dark jeans and a dark coat. It was never fully zipped up - she always had it half zipped or undone.
"I told them she looked the same as she did any other morning. To me, this was not a girl planning to disappear and never be seen again. This was a girl just making her way to work as normal."
Police have never publicly disclosed the mum's 8.20am sighting on TellyTubby Hill. They always referred to the last sighting, captured on CCTV, on Buzzacott Lane at 8.16am.
It was only during the second anniversary appeal that officers mentioned there had been another sighting, four minutes later, and just 14 minutes before Leah's phone inexplicably left the network in the area of Furzton Lake.
The mum said: "I was pleased when they told the public about it at last but I just don't know why it took them two years. I couldn't help feeling puzzled about it - and let down because it didn't seemed like they believed me.
"There's never a day goes by when I don't think about Leah and wish that she could be found. I even have recurring dreams about the case. It haunts me."
The mum plucked up the courage to speak out recently on the Facebook page called 'Leah Croucher Disappearance - Community Investigation'.
She said: "I really hope that the Citizen telling my story might jog somebody's memory and they will come forward with something that might help solve this heartbreaking mystery."
Yesterday the Citizen reported about another member of the public who felt she had been ignored after making a report to police in the early stages of the Leah investigation. This witness saw a man aggressively pushing a passenger down out of sight in a black car near Furzton Lake between 8.35am and 8.40am that morning. You can read our story here.
We asked the police why the mum's TellyTubby Hill sighting took two years to disclose. A spokesman said: “From the outset, this witness sighting was taken very seriously by the investigation team. It was balanced against other lines of enquiry that we focused on simultaneously.
“All material that we have released to the media and public as part of the investigation is carefully considered, and our investigation into Leah’s disappearance is ongoing.
“Any information that we receive is followed up, and we remain as committed as ever to finding out what has happened to Leah.
“We would continue to urge anybody who has any information that they feel may assist us to contact 101, quoting reference number 43190049929 or ‘Operation Dawlish’.
"If you have information and you would prefer to stay anonymous, call Crimestoppers free on 0800 555 111. There is a £20,000 reward."