The brother of a murder victim chased a dog walker with a samurai sword the day before his mother held a march against knife crime.
Mark Mathieson brandished the large weapon at Andrew Jack who had been out walking his dog in Glasgow's east-end.
The incident happened the night before his mother Michelle held an anti-knife crime march calling for tougher sentences on those who carry blades.
Her eldest son George had been fatally stabbed in November 2010 by Darren Smith, who was later jailed for life for the murder.
Mathieson was jailed for 17 months at Glasgow Sheriff Court on Monday after he admitted wielding the sword and acting in a threatening or abusive manner.
The court previously heard Mr Jack and a friend had been walking a dog around 7.20pm before visiting a takeaway restaurant in the city's Forge Retail Park in Parkhead.
Mathieson approached Mr Jack and challenged him to a fight. Mathieson walked off, but a person with him encouraged him to go back after Mr Jack.
Prosecutor Lynn McFauld said: "This other person was then seen to reach in to his jacket and retrieve a red handled samurai style sword which he allegedly brandished. The witness fearing for his safety started running from the scene.
"The other person was observed to hand the sword to the accused Mathieson who ran off in the direction of Jack."
The 19-year-old had been with his older brother George when he was stabbed through the heart during an attack in Cambuslang, South Lanarkshire, last year.
Darren Smith was jailed for a minimum of 19 years in June for the murder. The Mathiesons' mother Michelle became an outspoken opponent against those who carry knives after the killing.