PC James Campbell was working in the east end of Glasgow when he was shot by a robber in January 1919.
His killer, who is thought to have used a gun smuggled to Scotland by a soldier in the First World War, was never caught.
To mark the centenary of his death, the Scottish Police Federation has commissioned a permanent plaque to honour their fallen colleague.
The tribute was officially unveiled in Bannockburn cemetery, Stirling, yesterday.
It also records the deaths of PC Campbell’s two young children, who died within months of their father.
Records show the 39-year-old constable was critically injured after disturbing a gang of housebreakers in the back court of a tenement on what is now Tollcross Road in Glasgow.
He managed to grab one of the burglars, but he broke free and pulled a pistol from his jacket.
He shot the officer twice – in the neck and stomach – at point-blank range.
Despite giving colleagues a description of the gunman, the murderer was never tracked down.
Two days after the attack, PC Campbell died from his injuries in Glasgow Royal Infirmary.
Retired Chief Inspector Sandy Geddes, despite having no ties to the dead man, has been visiting PC Campbell’s grave since he was a young boy.
He said: “We regularly visited the cemetery and my mother would point out the grave and tell us all about ‘the brave Glasgow policeman’.
“So Constable Campbell became something of a legend to me and my family.
“My sister and I have been working for many years to keep the graveside in order, but due to its age that has proven more and more difficult as time has passed.
“That’s when I approached the SPF about helping us with a more permanent solution. When the idea of a plaque was suggested we were delighted.
“We are so grateful to the SPF for helping us keep his memory alive.”
Andrea MacDonald, chairwoman of the SPF, said: “It is an honour to pay tribute to an officer who gave his life to the service 100 years ago, particularly as this is also our own centenary year.”
At the time of his death, PC Campbell had been with the City of Glasgow Police for 18 years and was serving with the Eastern Division.
Hundreds gathered for his funeral, where he was described as an officer of “high quality and resource”.