The PSNI has made a specific appeal for anyone who was in the Markets area of south Belfast between 9.09am and 9.15am last Tuesday to help them hunt down the killers of Gerard Jock Davison.
This morning, one week on from the murder of the 47-year-old as he walked to work, police will return to the scene on Welsh Street in an attempt to find possible witnesses.
Davison left his home in the Markets just after 9am and was walking to work at a nearby community centre when he was shot five times.
The gunman is reported to be approximately 5ft 6ins tall and was wearing a black hooded waist-length rain jacket.
Detective Chief Inspector Justyn Galloway has set out two specific appeals for information.
"I want to hear from anyone who left the Markets between 9.09am and 9.15am last Tuesday, from any route, either on foot or in a vehicle, to contact detectives at Musgrave police station on the 101 number," he said.
"I also want to hear from anyone who parked a vehicle in the Markets before walking to work somewhere else.
"These people are potential witnesses and it is important that they come forward and talk to us. We will be talking to people this morning, handing out leaflets and posters and garnering as much information as possible."
He said the investigation had been "very challenging" and that they were following "a number of specific lines of inquiry".
"Officers will also be speaking to commuters at Central Station," he said.
"It is possible they may have seen someone or something of interest to our investigation and just aren't aware of its significance because of the proximity of the train station to the Markets. We will be talking to them to ensure we collect all the information we possibly can."
Three people have been arrested and released.