And there's more.
"Nero is charged with second-degree assault, misconduct in office and false imprisonment — charges that can only be proven if Gray was wrongly arrested, said Andy Alperstein, a Baltimore attorney who has represented police officers but is not involved in the Gray case. If the knife was illegal, “there is no case” against Nero and another officer, he said.
“If the facts were that the knife was illegal then the Gray arrest would be justified. Even if it wasn’t illegal and the officers acted in good faith, it would be the same result. All charges fail,” Alperstein said.
Marc Zayon, Nero’s attorney, argues in his motion that the knife in Gray’s pocket — described in charging documents as “a spring assisted, one hand operated knife” — is illegal under both Baltimore’s switchblade ordinance and state law. Gray was charged under the city ordinance, which has a different definition than the state law of what constitutes a switchblade."
http://time.com/3847891/freddie-gray-death-police-officer-baltimore/