FINGERPRINTING PREVIEW: William R. Kelley, chairman of the Junior Chamber of Commerce's civilian identification committee, is shown fingerprinting R. B. Finley, principal of Slauson School, while C. C. Crawford, assistant superintendent of schools, watches. Fingerprinting was to be demonstrated this afternoon in Slauson School as a prelude to the Junior Chamber's plan to obtain prints of all local public school children whose parents sanction the program. The fingerprints will be sent to the Federal Bureau of Investigation for its civilian files, used in identifying persons who are victims of amnesia, violence or a major disaster.