Altadena attorney Christopher W. Smith has been named assistant city prosecutor. Smith, 63, will manage the prosecution division of the combined city attorney and city prosecutor offices. He was chosen by City Atty. Victor Kaleta after a nationwide search. Smith, a 20-year veteran of the Los Angeles Police Department who retired from the force in 1967, has also worked in the county public defender's office and served in the Pasadena city attorney's office from 1967 to 1968. He has been in practice in Altadena for the last five years. Smith's new job will include prosecuting violations of municipal law and misdemeanor violations of state law.