Tactical gear—like body armor, ... New York bans most civilians from owning body armor unless they’re cops or security guards. Connecticut says you can’t buy it online—you gotta go in-person.

But security guards are not a panacea. For one thing, guards can be hard to hire. For its own security guard pilot program, Santa Fe, N.M., wanted 18 guards. Six months later, it still only has 12 ...