Here is a timeline of how the story has unfolded...
Wednesday 7pm, April 17: Bradley Welsh is training at Holyrood Boxing Gym
Wednesday 7.30pm: Mr Welsh drives outside his home and speaks to a neighbour before being shot in the head while walking down the steps to his flat.
Wednesday just after 8pm: A huge police presence descends on Chester Street with armed officers visible after several reports of a gunshot being heard.
Wednesday 10pm: Forensics are seen entering the basement flat to search for evidence.
Wednesday 11pm: The victim is named locally as Bradley Welsh.
Thursday 8am: People begin leaving floral tributes to the late Bradley Welsh.
Thursday noon: Police confirm the victim of the fatal shooting to be the Trainspotting 2 star.
Thursday 1pm: A forensic team is seen scouring Chester Street looking for clues as part of the investigation.
Thursday 3pm: Detective superintendent Allan Burton reveals to the media the details of the former boxer’s final moments and issues a public appeal for help in finding the man responsible.
Tuesday, April 23: Police Scotland reveal they have arrested, questioned and released a man in connection with the murder.
Wednesday, April 24: A second man is arrested, questioned and released by the murder squad.
Monday, April 29, 10am: Police Scotland reveal that on Saturday April 20, after exhaustive CCTV investigation and local inquiries, detectives and forensic experts descend on Kaimes Avenue in Kirknewton to seize a grey Ford Kuga, captured on a security camera in William Street near Mr Welsh’s basement home, at around 7.30pm on the night he died.
Sign up to our newsletter: enter your email in the box at the top of this article to get daily updates straight to your inbox.