James Attfield murder: Arrested man released without charge
A 38-year-old man arrested over the murder of a man in Colchester has been released without charge.
James Attfield, 33, died after a "frenzied" attack in the town's Castle Park on 29 March. He had been stabbed more than 100 times.
Det Ch Insp Simon Werrett said police had been given "useful information" after speaking to about 50 people during the course of Friday night.
They hope to trace two people who had been sitting on a bench in the park.
Mr Attfield was filmed on CCTV at the River Lodge pub in Middleborough, Colchester, at 22:09 GMT on 28 March.
Police do not know where he went between then and being found injured in the park.
Mr Werrett said: "We want to trace a man and a woman who would have been sitting on a bench in the park, by the lake. The only description is they were white and may have been smoking. This would have been about 23.30 on Friday evening.
"We also want to hear from anyone who may know someone who returned home early last Saturday morning with blood-covered clothing which they may have disposed of quickly."
Julie Finch, Mr Attfield's mother, said her son was "in the process of rebuilding his life" after suffering a severe brain injury when he was hit by a car four years ago.
"Someone, somewhere knows something. No matter how insignificant you may think it is, please inform the police," she said.
"The maniac who killed my son is still out there."
Det Ch Insp Simon Werrett said Mr Attfield, from East Bay, Colchester, was "a vulnerable man who would actively avoid confrontation and risky situations".
He added: "I am determined to ensure that James' family are able to see justice done and whoever is responsible for James' violent murder is taken off the streets."
Forensic investigations and searches are continuing.