DETECTIVES investigating the brutal murder of Jim Attfield have re-released a CCTV image of a man walking his dog who is yet to come forward.
The man can be seen walking through the park on Saturday, March 29, at 3.49am.
He has yet to come forward, despite the picture being shown on TV, online and in newspapers since April 10.
Police released more than 20 CCTV images of people walking in Middle Mill, close to Lower Castle Park, between Friday, March 28, at 10pm and March 29 at 5am.
They want to speak to potential witnesses and eliminate them from enquiries.
Mr Attfield, 33, of East Bay, Colchester, was found near Lower Castle Park with 102 stab wounds at 5.50am on March 29.
His killer, or killers, are still on the loose. Anyone with information is urged call Essex Police on 101 or Crimstoppers, which is offering a £5,000 reward for information, on 0800 555111.
A man and a woman, both aged 27 and from Colchester, are on police bail having been arrested in connection with the murder.