Essex police said detectives investigating the murder of Jay Whiston have set up a dedicated number for witnesses to call.
Anyone with information is asked to contact the incident room on 01245 452882.
Up to 200 people attended the house party in Colchester were the murder took place. For more on this story go to ITV Anglia.
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Derby was unable to play with other dogs after being born with severely deformed front legs - but can now run freely.
The judge said the 14-year-old had been subject to a great injustice. He was executed for the murder of two little girls in 1944.
It will be a dull and damp day today, with heavier and more persistent rain to the northwest and across Wales.