ALTHOUGH THE COURTS HAVE GENERALLY ATTEMPTED TO INTERPRET AND APPLY THE AGE DISCRIMINATION EMPLOYMENT ACT (ADEA) IN A LIBERAL MANNER, CERTAIN STATUTORILY DEFINED EXCEPTIONS SUCH AS THOSE RELATING TO REASONABLE FACTORS AND BONA FIDE OCCUPATIONAL QUALIFICATIONS HAVE ALWAYS BEEN RECOGNIZED AS BEING AVAILABLE FOR USE BY THE LAW ENFORCEMENT EMPLOYER. WHENEVER AN AGE-BASED CLASSIFICATION HAS BEEN CHALLENGED UNDER THE ADEA, AN EMPLOYER MAY SHOW THAT DENIAL OF EMPLOYMENT TO CERTAIN AGE GROUPS IS LEGITIMATE BY PROVIDING THAT THE AGE QUALIFICATION IS REASONABLY NECESSARY TO THE ESSENCE OF THE BUSINESS AND HAS REASONABLE CAUSE I,E., A FACTUAL BASIS FOR BELIEVING THAT SUBSTANTIALLY ALL PERSONS WITHIN THE CLASS WOULD BE UNABLE TO SAFELY AND EFFICIENTLY PEFORM THE DUTIES OF THE JOB INVOLVED OR THAT IT WOULD BE IMPOSSIBLE TO DEAL WITH PERSONS OR AN INDIVIDUAL BASIS. COURTS, HOWEVER, HAVE BEEN UNABLE TO DETERMINE THE AMOUNT OF EVIDENCE REQUIRED FOR AN EMPLOYER TO ESTABLISH THIS FACTUAL BASIS. LAW ENFORCEMENT EMPLOYERS CONCERNS FOR PUBLIC SAFETY MANIFESTED IN AGE OR SEX REQUIREMENTS, WOULD SEEM TO CONFLICT THE DEPARTMENT OF LABOR, EFFECTIVE ENFORCEMENT OF THE ACT. IT IS CLEAR THAT THE BURDEN OF PRODUCING SUFFICIENCY OF EVIDENCE, AS WELL AS THAT OF PROOF AT TRIAL, IS ON THE EMPLOYER. FOOTNOTES ARE GIVEN. SEE ALSO NCJ-64213. (AUTHOR ABSTRACT MODIFIED--MJW)