A single medium-caliber mortar is a five-hundred-year-old piece of technology that can be carried and assembled by two men, has an effective range of ~1,000 to 5,000 yards, does not require line of sight to the target, can be operated by a high-school dropout, and has a kill radius of 30 meters.
One can probably be picked up from an army surplus warehouse somewhere in the former Soviet Union/(some current conflict zone), for an ~$X,000 USD bribe, or alternatively, manufactured by a literate, mildly motivated individual with a high tolerance for personal risk, a welder, a lathe, a tool-shed, and an outhouse in the mountains.
Given that we live in a world where gunpowder has been invented, you will have to pardon me if I'm more concerned about the dangers of lunatics with mundane explosives, and delivery systems thereof.
For an assassination of a specific target - even with military equipment and technology, it would be dubious to use a mortar. They simply are not precision weapons, as you already pointed out.
But, for inflicting terror and great loss of life in a populated area - they could be used very effectively.
One can probably be picked up from an army surplus warehouse somewhere in the former Soviet Union/(some current conflict zone), for an ~$X,000 USD bribe, or alternatively, manufactured by a literate, mildly motivated individual with a high tolerance for personal risk, a welder, a lathe, a tool-shed, and an outhouse in the mountains.
Given that we live in a world where gunpowder has been invented, you will have to pardon me if I'm more concerned about the dangers of lunatics with mundane explosives, and delivery systems thereof.