The man shot in Hove at the weekend was killed by a single bullet to his abdomen.
Xhem Krasniqi, 31, died after being shot in Church Road, Hove, near the junction with Selborne Road, on Saturday night (18 May).
Post-mortem tests carried out last night (Monday 20 May) concluded that Mr Krasniqi was hit once in the abdomen.
He was taken to the Royal Sussex County Hospital in Brighton and died there shortly afterwards.
He had been with his brother and nephew when they were shot at in the street. Neither of them were injured.
Detective Chief Inspector Jeff Riley, from the Surrey and Sussex Major Crime Team, said: “Xhem’s family are extremely distressed and we are offering them the support of our family liaison officers.
“I have assured them that we are doing all we can to trace his killer and ensure he is brought to justice.
“I would like to thank the local community for their support and patience while this investigation is ongoing.
“They have been helpful in telling us what they saw that night. We have taken this information and are undertaking intelligence work in an effort to trace those we would very much like to talk to.
“We believe the men all knew each other and we are open-minded as to the motive.
“The initial indication is that there’s a personal dispute between some members of two families and that this has escalated dramatically, leading to Xhem’s tragic death.
“This has been a distressing incident for local people, especially those who witnessed the shooting, but I can assure them that this was not a random incident.
“I would urge them to talk to neighbourhood policing officers if they have concerns.”
Anyone who has yet to come forward with information is urged to contact Sussex Police on 101 or the independent charity Crimestoppers anonymously on 0800 555111.