You call that a knife

Reason tries to sort out the type of knife that is legal and the type that's illegal.
If police and prosecutors cannot agree on whether Gray's knife was legal, of course, it is hardly fair to expect the average citizen to know, let alone subject him to criminal penalties (a fine up to $500 and up to a year in jail under Baltimore's ordinance) for guessing wrong. Furthermore, the fuzziness of this ban, like the fuzziness of offenses such as loitering and disorderly conduct, invites arbitrary and discriminatory enforcement. The Christian Science Monitor's Patrik Jonsson makes that point in a story that asks, "Should it really be illegal to carry a knife in the city?"