THE murder of Nahid Al-Manea is due to feature on BBC Crimewatch tonight.
Police hope the short appeal will prompt witnesses to come forward and help move the investigation on.
A senior detective has dismissed claims police are running out of ideas as they attempt to solve two murders in Colchester.
Nahid Al Manea, 31, of Woodrow Way, was stabbed 16 times and murdered on the Salary Brook Trail shortly before 10.40am on Tuesday, June 17.
Jim Attfield, 33, of East Bay, was stabbed 102 times and discovered on the morning of Saturday, March 29.
The killer, or killers, have not been found.
Det Chief Supt Steve Worron said police have dismissed a number of possible motives and have many active lines of investigation, although he would not give specifics for operational reasons.
Crimestoppers is offering rewards of up to £10,000 for information leading to the conviction of the killers of either victim.
Detectives are still searching for a significant number of potential witnesses.
They include: A man who is thought to have been wearing a designer Italian jacket, slightly longer than waist-length, with brown buttons up the front and two pockets also with buttons.
It was beige and had a belt.
He was seen on the Salary Brook Trail between 10.20am and 10.40am, shortly before Nahid was found.
He was walking towards the Greenstead estate on the Salary Brook Trail.
He is described as having thick, short black hair and aged in between his late teens to 30s, 5ft 6ins tall and of average build.
Also two cyclists who were seen using the trail on the morning that Nahid was found.
The man and woman were cycling together and may have seen Nahid after she was attacked.
They were seen by a witness at 10.45am on Tuesday, June 17, coming from the direction of the university towards Greenstead on the Salary Brook Trail.
The man is olive skinned with dark hair. He was in his early 20s and was tall and slim.
The woman is thought to be in her 20s with long dark hair. She was wearing what has been described as a flowing pattern tiered skirt.
A tall man in a trilby style hat who was seen in the area around the time of the murder may also be a witness.
He is slim and was wearing a long dark trench style coat. His hat may have been green or dark blue and he had long dark wispy hair.
A white man, aged between 19 and 23-years-old, with blond hair.
He was wearing a back pack and white headphones and may have been a student.
A white man, also thought to be a student, who had dark, short hair. He was wearing light trousers and was using a phone.
A black man who was wearing a forward facing cap and a back pack. He was also wearing a dark blue and yellow striped polo top.
Two women on bikes, who were seen by the hedgerow on the Salary Brook Trail
A white woman with long blonde hair, 5ft 10ins tall, of slim build and aged around 19 or 20 who may have been a foreign student.
And a young man on a bike, also seen on the Salary Brook Trail, around the time of the murder.
Mr Worron said: "I would like to thank the local community for their support with our investigation.
"Featuring the appeals on Crimewatch will really help us to capture information from people who may not have seen some of the local media reports.
"They may not be Colchester residents but may have been visiting the area for work or social reasons on the day Nahid was murdered.
"Any information they have could really help us as we continue with our investigations.
"We would really like to speak to anybody who was on the Salary Brook Trail between 10.15am and 10.45am on Tuesday, June 17.
"Please come forward. Call the incident room on 01245 282103 or Crimestoppers anonymously on 0800 555 111.”