Police investigating the death of a teenager whose body was found on the queen’s Sandringham estate have confirmed that the girl is Alisa Dmitrijeva, a 17-year-old student from Latvia.

The formal identification comes a day after Alisa’s mother told the Mail on Sunday newspaper the distressing story of how the family had fled poverty in Eastern Europe for a new life in Britain.

Anzela Dmitrijeva, 34, described escaping a life a world away from the imposing splendor of Sandringham and its grounds, where a dog walker stumbled across Alisa’s body on New Year’s Day.

Mrs. Dmitrijeva said she and her husband Olegs, 40, had been struggling financially while they raised Alisa and her little sister Victorija, now 10. The family had been living in a ground floor apartment in a Soviet-era building in the bleak and depressing suburb of Kurzemes, half an hour’s bus ride from Riga, the Latvian capital. The grim flat had itself been the scene of the murder of a 7-year-old girl some 20 years earlier, a fact that disturbed Mrs. Dmitrijeva.

She had been close to her eldest daughter growing up, but everything changed in 2008, when she was forced to leave her children behind in Latvia to take a job at a food-processing company in Boston, Lincolnshire.

“When I left for Britain three years ago, seeking a better financial situation for me and my family, Latvia was facing a bad time with the economy and there was a necessity for me to find a job,” she told the Mail. “I know now I should have taken her and the family with me and not left them behind.”

The rest of the family arrived in Britain a year later and they settled in Wisbech, Cambridgeshire. Alisa found the transition difficult, Mrs. Dmitrijeva said, adding that she now believes her yearlong absence had “made a division in the family.” Mrs. Dmitrijeva subsequently moved out of the family home. Alisa stayed with her father and sister, and their grandmother joined them.

In the months leading up to Alisa’s disappearance, the strain worsened. “In Britain, Alisa changed so much,” her mother said. “Since April this year, we started arguing, badly and strongly."

Family photographs chart a change: a fresh-faced girl who looks young for her age—her wavy hair tied unselfconsciously in a ponytail—becomes a young woman keen to look older with her straightened hair, posing unsmiling in a short skirt, tight shirt, and heels.

“The last time I saw Alisa was in July and it wasn’t a friendly meeting,” Mrs. Dmitrijeva said. “She came to me saying she needed money.” The girl had been arrested for stealing and had started taking drugs.

In August, Alisa vanished. At first, her mother was not overtly worried. They’d argued. It had been unpleasant. But she felt sure her daughter would return.

“Then something really kicked me in my heart,” she told the Mail. “I took her picture and went ’round the local shops in Wisbech, desperately looking for her.”

On Sept. 6, her grandmother filed an official missing persons report to the police. Authorities established that Alisa was last seen just after midnight on Aug. 31 in the town of King’s Lynn getting into a green Lexus with two male friends.

According to a Mail on Sunday source, those men have been traced and interviewed. They told police that they had dropped Alisa back in Wisbech, near the Asda supermarket. There is no CCTV footage to corroborate their evidence.

Although Alisa’s body was discovered in a small wooded area over a week ago, the painstaking identification process has taken longer than expected.

It had been an anxious wait for Alisa’s family. Police issued details of the deceased, including her “high cheekbones” and 5-foot-6 height, which matched Alisa.

The condition of her remains was such that despite numerous tests—on samples from the tooth, femur, and muscle of the calf—pathologists were not initially able to establish a useable DNA profile. On Sunday afternoon a positive comparison was made on a detail from her palm with records held. Bone samples that were made into a powder for more accurate analysis finally produced a DNA match.

Police teams had already called in specialists from other fields to get a better idea of the time frame of the murder. Among them an academic from the Natural History Museum in London, who carried out entomological tests to establish how long the body had been left in the wooded area, a mile from the gates of Sandringham House.

Police said immediately that the circumstances around the young woman’s death were suspicious, but the cause of her death remains a mystery. A postmortem examination by Dr. Nat Cary, a Home Office pathologist, was unable to find evidence of injury through firearms, a bladed weapon, or other trauma such as broken bones.

Detectives are due to interview employees at Sandringham, including workers and the queen’s grooms at her nearby stud farm, to see if they can help the investigation. Officers are not expected to question any members of the royal family, although the queen has asked to be kept informed.

On Saturday neighbors in Latvia remembered Alisa as a friendly child growing up. Donat Izich, 73, told the Mail she was “a nice girl, always smiling.”