Joseph Harvey Jr. , a Maryland detective , is charged with second -degree murder . CNN say he fatally shot driver Walker , after an altercation . Walker 's wife , kids were with him during the apparent road-rage incident , police say .
Joseph Walker , a New Jersey detective , is charged with second-degree murder . Maryland State Police say he fatally shot driver Joseph Harvey Jr. , after an altercation . Walker 's wife , kids were with him during the apparent road-rage incident , police say .