After nearly 10 years, the investigation into the disappearance of Claudia Lawrence remains unsolved.
Despite numerous appeals, searches, arrests and interviews, there are still no answers to the question of what happened to the 35-year-old on March 18, 2009.
In the days after Miss Lawrence was reported missing, police said they were keeping an "open mind" about what had happened but said it was "a possibility that an abduction could be involved".
It was believed that the university chef set off on her three-mile walk to work on the morning of March 19 and searches were initially focused on the route between her home on Heworth Road and the University of York.
Hundreds of North Yorkshire Police officers were involved in the search and officers from other forces were brought in to help.
But there was no CCTV footage of Miss Lawrence on her usual route to work and Detective Superintendent Ray Galloway, the senior investigating officer at the time, said he believed she was with, or had gone with, someone she knew.
Within two weeks of her disappearance, police had made a national television appeal for information on the BBC's Crimewatch programme, which led to information about a previous relationship.
Locally, police appealed for a number of people and vehicles to come forward, including a couple seen arguing and a left-handed smoker.
And CCTV footage was released of a man seen to the rear of Miss Lawrence's house on the morning of March 19.
Searches included nearby properties, the Nags Head pub and areas of land near the University of York.
On April 24, 2009, police said they were now treating the investigation as suspected murder.
The investigation began to focus on Miss Lawrence's personal relationships, with Mr Galloway appealing for information on Crimewatch, saying it was apparent that some of her relationships "had an element of complexity and mystery to them".
He later said he believed she had been harmed by someone she had been in a sexual relationship with.
Six months after she disappeared, police said they had extended their investigation to Cyprus, where they went to speak to people Miss Lawrence knew on the island.
The investigation was scaled back 16 months after her disappearance but in 2013, Detective Superintendent Dai Malyn began a review of the original investigation.
As part of the review, officers undertook a new two-month forensic search of Miss Lawrence's home, which uncovered fingerprints of people who had still not come forward five years after she went missing.
The team also found the DNA profile of an unknown man on a cigarette butt in Miss Lawrence's Vauxhall Corsa.
A number of new appeals were issued to trace people and vehicles seen around Miss Lawrence's home at the time of her disappearance and a fingertip search was conducted in the alleyway behind her home.
The review led to a number of arrests. A 59-year-old man arrested on suspicion of murder in 2014 and a 47-year-old man arrested on suspicion of perverting the course of justice were both later released without charge.
Four more men were arrested on suspicion of murder in 2015 and files were submitted to the Crown Prosecution Service but charges were not brought.
Six years after her disappearance, Mr Malyn said he was following up a number of new leads and warned anyone who had not yet revealed information about their relationship with Miss Lawrence to come forward or risk being arrested.
The detective said some people had kept their relationship secret and some had deliberately lied about a number of issues concerning their association with the chef.
In January 2017, it was announced that the investigation would move into a reactive phase and only review new information.
The final part of the review saw officers travelling around the UK to try to obtain DNA from people with similar DNA profiles to unidentified samples recovered during the investigation.
But the DNA analysis concluded without identifying a possible suspect or suspects.
Assistant Chief Constable Paul Kennedy said: "Despite their exhaustive efforts, the support of national experts, the application of the very latest forensic techniques to exhibits recovered many years ago, and despite the team tracing and speaking to many people who did not come forward in the first enquiry, we have sadly not been able to find that crucial piece of information."
But Mr Malyn said the investigation will always remain open.
Speaking in 2016, he said: "I'm hopeful one day we will get that bit of luck or that a courageous person will step forward to give us that break."
By Amy Murphy, Press Association