Detectives are using GPS tracking records as they try to track down cars and vans that could be crucial to the John McMurchie murder investigation.
Around 30 vehicles have been spotted on CCTV footage in and around the area of Dundee where the father-of-five was stabbed in the heart.
Officers have been trying to identify and question the drivers, but have also widened the search to anyone passing through Dundee around the time Mr McMurchie was killed.
Detective Inspector Bobby Dow said the technology was being used to find motorists who could help the inquiry.
”Predominantly the inquiry team is focused on identifying anyone out and about in the area at the time of the murder,” he said. ”We want to speak to anyone who was in the area between 3am and 4.30am on August 12.
”That means we are looking at shift workers, delivery drivers, taxi drivers and drivers who were just going through Dundee. A lot of technology is going into this, like GPS tracking for the vehicles.
”We also want to speak to door staff on their way home from working in town.”
Officers have identified a number of other house parties that were going on in Whitfield and Fintry the night of the murder. They have spoken to people at these parties as potential witnesses.
Mr McMurchie was found seriously injured about 4am on August 12 on Fintry Terrace, near to its junction with Whitfield Drive.
He was taken by ambulance to Ninewells Hospital in Dundee where it was later confirmed that he had died of his injuries.
DI Dow said officers were still scouring CCTV footage in a bid to try to track down anyone who might have seen the murder.
Anyone with information should call Tayside Police on 0300 111 2222, or speak to any officer.