Nahid Almanea, 31, was stabbed on Salary Brook Trail, Colchester, on 17 June last year.
Essex Police said its investigation was continuing at a "significant pace".
But the force is continuing to look for a man seen wearing a "distinctive jacket" on the trail.
In the days after Ms Almanea's death, detectives issued a description of the man, who was wearing a "beige Italian style designer jacket", saying they "urgently" needed to speak to him.
About 950 potential witnesses had been spoken to, more than 1,300 statements taken and 4,546 exhibits seized, the force said.
No one has yet been charged in connection with Ms Almanea's death.
Just over half of the 88 people captured on CCTV images released as part of the investigation have been identified, a police spokeswoman said.
Efforts are continuing to conduct forensic tests, review security camera images and speak to witnesses.
Det Ch Insp Mark Hall, who is leading the investigation, said: "This is a complex and large scale investigation but we remain focussed on pursuing each piece of information in order to identify the person or persons responsible for Nahid's murder."
Searches for a man seen near to where a Saudi Arabian student was murdered have been unsuccessful, despite almost 1,000 potential witnesses being spoken to, police said.