Friends of murdered pub worker Iuliana Tudos have described her as "funny, honest, loving" and "definitely something special".
A post-mortem examination concluded that the 22-year-old, whose body was found in a disused building in London's Finsbury Park on Wednesday afternoon, died from a stab wound to the abdomen and a head injury.
Further tests are being carried out. A crime scene remains in place, police said on Friday.
There are no arrests as yet over the murder of Ms Tudos, who was also known as Julia and Lili, and lived in Upper Tollington Park, Haringey.
Officers, who are appealing for information, are "working to piece together a timeline".
Iuliana's family, who are currently living abroad, are "naturally devastated", they added.
One of Iuliana's friends, Sonny Webb, told Sky News she was "like my little sister".
"She was a lovely person to be around," he added, "a caring person. She meant so much to me and the world is not going to be the same without her."
Another friend, Senya Taylor, described Iuliana as "an awesome person".
"She was definitely something special," she said. "Very kind, fun, generous, life loving. I loved spending time with her."
Sylvia Legin said Iuliana's laugh was "one and only", adding: "I still can hear it between the walls of my room."
"We believe that she was attacked where she was found," said DCI Nicola Wall.
"Our enquiries from CCTV footage have now ascertained that Iuliana was seen on the periphery of the park on Christmas Eve, shortly after 20:20hrs."
DCI Wall added: "We want to hear from anyone who saw, had contact with, or heard from Iuliana after this time.
"We'd also like to hear from anybody who saw anything suspicious within the park over the Christmas period."
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Extra officers have been deployed to reassure local residents.
Anyone with information should call the incident room on 0208 785 8244, or contact Crimestoppers, anonymously, on 0800 555 111.