I think that this item can be a trophy of the Franco-Chinese War of 1884-85. Then the French troops captured many of these weapons. The ornament, consisting of small circles with a dot in the center, is characteristic of peoples living in northern Vietnam near the border with China.
Could this item become an instrument of execution? Yes, he could. But this is definitely not its main purpose.
Here is a very good comparison of similar items of the Vietnamese and Chinese types.
https://www.mandarinmansion.com/arti...ietnamese-arms