A fifth teenager has been arrested over the death of an A-level student who was stabbed outside a house party.
Jay Whiston, who was 17, was knifed on Saturday night at the gathering that was attended by about 100 teenagers in an affluent area of Colchester.
Essex Police said a 17-year-old was being questioned today on suspicion of assault after being arrested in the town yesterday.
A 17-year-old boy and two 18-year-old men remain in custody at separate police stations in north Essex being questioned on suspicion of murder.
A 17-year-old boy, who had also been arrested on suspicion of murder, has been released without charge, police said.It is believed details of the event were circulated on the social networking site Facebook and a number of uninvited guests turned up.