A fourth person has been arrested on suspicion of murder after a man was found in the street in what police believe was a targeted stabbing.
Lee Chapman, 26, was found on Cromer Street, Southend-on-Sea, Essex, at about 23:50 GMT on Friday.
A 17-year-old boy, from Southend, was arrested on Sunday afternoon.
Three other people had already been arrested and questioned: a 16-year-old boy, a 44-year-old man and a 45-year-old woman.
Mr Chapman was taken to hospital, but was pronounced dead on arrival.
Essex Police said officers believed the attack followed followed a fight.
A group of people was seen leaving the area in a dark Mercedes and investigators are continuing to appeal for information.
Temporary Det Ch Insp Julie Gowen said: "Our investigation into this attack is progressing well and we are building up a picture of the events which led up to it.
"I appreciate incidents like this can cause concern to the local community but we believe this was a targeted attack with no risk to the wider public."
The 16-year-old remains in custody, while the man and woman have been released on police bail until next month.