Detectives were on Sunday night due to revisit the scene of the murder of Natalie McNally three weeks after the mother-to-be was stabbed to death in her home in Co Armagh.
Lead investigator Det Chief Insp Neil McGuinness said police intended to speak to motorists and pedestrians in a “determined attempt to jog memories”.
Police on Saturday seized a car from an address in the Lisburn and Castlereagh area, which was taken away for further examination. House-to-house enquiries were also carried out in the Lisburn area.
Ms McNally, who was 32, was attacked in her home in the Silverwood Green area of Lurgan on December 18th. She was 15 weeks pregnant at the time of her death.
The senior detective said police were still attempting to identify a man who was captured on CCTV carrying a rucksack as he arrived to Ms McNally’s street on the night of her murder and was seen leaving shortly afterwards.
The footage has been released to the public, and Det Chief Insp McGuinness appealed for people to “keep this image firmly in your mind”.
“You’ll see the suspect arriving at Silverwood Green that night at 8.52pm, and you’ll see the same figure walking away at 9.30pm,” he said.
“Please remember, this was the night of Sunday 18 December – that’s the same day as the World Cup Final. I’m asking you to cast your mind back to that Sunday. If you witnessed anything untoward – no matter how insignificant it may seem – or if you have captured dash cam or CCTV footage, please get in touch.”
The CrimeStoppers charity has offered a £20,000 reward for information leading directly to the arrest and conviction of Ms McNally’s killer. Police said last week that their main line of inquiry was that Ms McNally knew her killer, and he was someone she was comfortable allowing into her home.