Hello egar,
The incident was reported in the Times newspaper. Perhaps you have already seen this:
Tuesday July 2 1929
GLASGOW SHOOTING AFFAIR
A woman named Agnes Young, of Drygate, Glasgow was shot dead and a man named Daniel Owens of London Road, Glasgow was wounded in Glasgow last night. It is stated that, while they were ina public house in the Gallowgate in the east end of the city, a man without warning pulled a revolver from his pocket and shot the woman in the throat. She collapsed and while she lay on the ground the man fired two more shots into her body. Apparently she was killed by the first bullet. Another man in the public house ran to the woman’s assistance. He was shot by the assailant, who then rushed into the street and tried to escape. A crowd gave chase and the man brandished his revolver but was overpowered. The alleged Assailant was taken into custody and charges of murder and attempted murder were preferred against him.
leighton