sports gambling has been going for several years in UK and several other countries. i dont remember anyone getting murdered over a lost bet.
https://www.independent.co.uk/news/uk/crime/father-jailed-fo...
https://www.independent.co.uk/news/uk/gambler-murdered-woman...
It's a bit hard to find good stats, but it's at least 1 or 2 a year, it could be more like 10 - plenty of domestic violence is caused by money problems, and those problems can often be gambling related.
There's a lot of suicides - between 250 and 650 people each year according to gamblingwithlives.org https://www.gamblingwithlives.org/wp-content/uploads/2022/01...