A NEW investigation into the death of murdered prostitute Rachel Wilson has been launched with officers revisiting almost 5,000 people.
Detectives say they have a 'strong case' and remain positive that the 19-year-old's killer will be found more than ten years after her death.
Rachel's disappearance from her home town of Middlesbrough in June 2002 led to one of the biggest missing persons inquiries ever mounted by Cleveland Police.
Last June, ten years on, her body skeleton was found in a shallow grave at near Coulby Newham, Middlesbrough.
She had been a sex worker but had no reason to disappear.
A post-mortem examination was carried out but a cause of death could not be established.
"The only major piece of evidence we have from the discovery of her body is the location," said Detective Superintendent Peter McPhillips who is leading the murder investigation.
"It is a very remote spot, whoever killed her must have known that area and been there before."
A team of 20 officers is now working on the murder investigation.
Its members are currently involved in revisiting all the people who have been involved in the case since it opened in 2002.
Det Supt McPhillips said: "There are about 4,600 people who have been involved or spoken to throughout the investigation - this includes police officers who have worked on the inquiry, other sex workers and potential witnesses.
"We are using a system that we have never used before.
"We contacted the National Missing Person’s Bureau and the National Policing Improvement Agency to give us some advice about this type of inquiry and what we should do.
"They advised us to do a scoring system which is what we are ongoing with now."
Each person who has had involvement in the case is given scores for different categories, for example their level of danger and how heavy their link is to Rachel's disappearance.
The people with the highest scores will then be looked at more closely.
Det Supt McPhillips said: "Eventually we will have a table of individuals with their different scores.
"We are also revisiting all the sex workers involved in the case - which is 262.
"They were all working in this area at the time Rachel disappeared. Some are no longer sex workers, some are now deceased and some are no longer living in this area."
One of the questions the detectives are asking the sex workers is whether they visited the area in Coulby Newham where Rachel was found, with their clients.
Det Supt McPhillips said: "At the moment we are getting intelligence that sex workers did go to that area with clients.
"At the time of Rachel's disappearance police were very proactive in stopping prostitution and they would patrol the town centre a lot so clients tended to take them outside the area so they wouldn't be seen by us."
Det Supt McPhillips said the post mortem carried out on Rachel's skeleton led to very little extra evidence for his team.
He said: "We do not have a cause of death and we don't know if she was killed at the spot where she was found.
"She had no clothes on and there was no murder weapon found at the scene."
Rachel's mum Tina Wilson, from Grove Hill, Middlesbrough, said she has faith in the police and is hopeful that they will one day find her daughter’s killer.
She said: "I am always hoping that one day I will get that call saying they have someone.
"The police visit me every week to talk about where they are at and what they are doing with the investigation.
"They are doing a great job and I have a lot of confidence in them.
"My family will not get closure until they find Rachel's killer."
Mrs Wilson visited her daughter's grave on Christmas day last year with her family.
She said: "We had a quiet Christmas with all the family together. We went to see Rachel on the day.
"There were times when I feared that would be something I would never be able to do."
Funding is a problem for the murder team as it relies on money from the Major Incidents Fund - which was affected by last year’s cuts in the force.
Det Supt McPhillips said: "Funding is a nightmare really. And we have to be careful with that. Last year we had a few lengthy and costly murder investigations including the James Allen case.
"But generally the number of murders has decreased in the force - the average amount is normally eight or nine murders a year and last year there were three murders as well as Rachel's case."
Det Supt McPhillips said he has a lot of hope and confidence that Rachel's killer will be found.
He said: "I still think we have a strong case. It is such an unusual location and isn't a place that we expected to find Rachel. We can hopefully link the suspect to that location."