The killing of Watton teenager Johanna Young at Christmas 1992 became Norfolk's biggest ever murder inquiry. But 26 years later the case remains unsolved. This is what our new podcast found out.

The podcast from the Eastern Daily Press, called Unfinished, has re-explored Johanna's death and heard information never made public before.

•Man in a van

A witness we've never heard from before came forward in episode three of Unfinished.

He said the night the 14-year old went missing, December 23, 1992, he saw a young woman arguing with a man in a van at the junction of Griston Road and Norwich Road in Watton. That is close to where Johanna's body was found three days later.

The man, who was 27 at the time, said he was driving home at around 9.30pm, and was passing the junction when he saw a man sitting in a van.

The driver was arguing with a young woman standing next to the vehicle, which he believed was silver coloured.

He said they were gesturing and had raised voices.

He knew Johanna but could not make out if it was her. He believed he recognised the Luton-style van but could not see the man's face.

He said he passed a first name onto police - the name of the man he believed owned the van.

The witness himself was quizzed by police at least twice at the time and said he had a DNA sample taken.

No appeal was put out about the information he gave detectives. He said he also came forward again to police several years later to report what he had seen. Again this information was never made public, but he is the second person to see a young woman and man in the area that night.

Another witness saw a teenage girl and young man leaning on a motorbike at around 9pm that evening by the junction.

•School break-in

Jan Godfrey, the deputy teacher at Johanna's school, said she remembered Wayland High, which Johanna lived opposite to, being broken into the night Johanna disappeared.

Johanna left her home on Merton Road at around 7.30pm and was last seen alive on Watton High Street at around 8.30pm. It was cold and foggy and there were not many people around.

Police were desperately searching for witnesses and leads to help them solve Johanna's death, but PC Peter Walmsley, who was the police's spokesman during the case, said he did not remember the break-in being reported to police.

He said it was very difficult to get information out of the school.

The school's deputy headteacher Jan Godfrey said she thinks the caretaker reported the break-in to police, but she can't be sure.

This is important because police believe Johanna's killer was a young, local man - possibly a pupil or ex-pupil.

•Police lost trust

We hear how police treated witnesses as suspects which put people off coming forward with information.

But Vivian Sellers, who ran a taxi firm in the town with husband Adrian, said she was even asked to change evidence by one officer.

Johanna worked at weekends and holidays at their taxi company and was there the morning of December 23.

Adrian and his son were both working the night Johanna disappeared and at different points both drove a red Peugeot estate car, which a witness saw and flagged up to police. They were asked for statements and gave them.

Vivian and Adrian both said that an officer then tried to get them to change the times in their taxi log to fit with the police's narrative.

The exact reason for why the officer needed the timings to change is unclear. Police have refused to answer any of our questions about this case.

•Last friend

One of Johanna's last friends to see her alive also came forward in episode three. She saw her on Watton High Street on the day she disappeared. She said she seemed down and that has been put down to the fact she had split up with her boyfriend, Ryan, two days before she disappeared. He was questioned by police but quickly ruled out as a suspect and had an alibi for that night.

The friend said: 'I remember asking her if she was OK and yes she did seem down. I wish now that I had more time back then to talk to her.'

•Late-night parties

PC Walmsley said he believed Johanna had gone out to a party the night before she disappeared and was dropped off by a taxi driver a short distance from her home. Two other witnesses also reported giving Johanna lifts home late at night from parties in Dereham.

Watton's youth scene became a focus of the police investigation as officers tried to find out more about Johanna's world and the world of the main suspect.

•At least two people involved

The one bit of useful forensics police found were drag marks on Johanna's back. They matched drag marks by the water-filled pit near Wayland Wood where Johanna's body was found. That meant she was probably dragged in a U-shape with one person holding her top half and the other person her feet.

•Manslaughter?

Evidence gathered by police suggested that Johanna may have been killed by accident. The coroner at her inquest in 1993 said: 'What may have started as a youthful prank finished up in tragedy.'

Johanna is believed to have been knocked unconscious by banging the back of her head in a fall, meaning she was still alive when put in the pit.

PC Walmsley said police should have treated Johanna's death as manslaughter rather than murder to encourage people to come forward.

He said he told the lead investigating officer: 'If you put this out as manslaughter and not murder you might get someone to come in.'

But PC Walmsley said he was overruled.

•Jeans and DNA

The day Johanna's body was discovered, police also found her shoes and underwear - but not her jeans.

Then on January 19 1993 her jeans appear close to where her body and clothes were found four weeks earlier. They had been washed and there was no DNA on them.

Where were they between her death and four weeks later when found strewn on a bush by Griston Road?

Retired Norfolk police officer, Chris Clark, who now investigates cold cases, said the killer likely believed his DNA was on the jeans which is why he took them. There are also no signs of a struggle which means, he suggests, that her shoes, jeans and underwear were removed after she had been knocked unconscious.

•You can listen to all three episodes on iTunes or by searching for Unfinished on your usual podcast provider.

•Anyone with information about this case can contact Crimestoppers anonymously on 0800 111 555

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