Neighbours heard a "screech of tyres and blast of a horn" in the moments after a woman was murdered in the quiet cul-de-sac of Raeswood Drive, Crookston.
And almost three hours before Isabelle Sanders died and her partner Norman Busby was attacked, the killer stabbed a driver in an attempted carjacking.
Detectives today appealed for the car driver to come forward after revealing the killer - who stabbed Ms Sanders, 51, and Mr Busby, 85, in a botched robbery - was almost knocked down as he made his getaway in nearby Crookston Road.
Detectives from the major investigations team have identified a suspect, but remained tight-lipped about his identity.
Detective Super-intendent Jim Kerr said: "We easily could have been dealing with a double murder here."
It comes as police revealed the culprit stabbed a 33-year-old motorist in the leg during an attempted carjacking almost three hours before Ms Sanders was killed.
That incident took place outside a Spar shop in Barrhead Road, around 700 yards from Raeswood Drive, at 11.15pm on Tuesday.
Shop manager Asif Sharif told how the BMW driver escaped the clutches of a killer outside his store.
He said: "The man had been stabbed in the leg and came back into the shop for help.
"On the CCTV foot-age, you could see him running back in from the car, it must have been the adrenaline.
"My staff helped him and phoned an ambulance. We are still trying to come to terms with it all."
However, the attacker dropped the keys and did not drive away in the BMW.
Police said the driver is recovering at home.
Ms Sanders and Mr Busby were attacked in their home after disturbing the intruder early on Wednesday.
The 51-year-old died at the scene, and her partner is recovering in hospital from stab wounds.
Forensic officers were yesterday searching drains in Raeswood Drive as detectives tried to piece together the killer's movements in the hours between the incidents.
Detective Superinten-dent Kerr, added: "Please do not assume that we already know what you know, or that someone else has come forward with the information you have.
"As a result of the support from the public and information passed, I would like to reassure the comm-unity that we are following a definite line of inquiry in relation to the murder of Isabelle Sanders and the attempted murder of Norman Busby.
"I am appealing for the drivers of particular vehicles to come forward.
"Firstly, the driver of a private hire taxi which was in Raeswood Drive at the time of incident. Secondly, I would like to speak to any drivers who were on Crookston Road around 1.50am on Wednesday to come forward, particularly if you saw a man running across the road."
Police also revealed items had been stolen from Ms Sanders and Mr Busby's home, but could not give details.
A car, which was parked in the driveway, remained covered in blue tarpaulin until it was removed by officers.
Anyone with infor-mation is asked call Police Scotland on 101.