A claim of disparate treatment is examined under the three-party analysis
first enunciated in McDonnell Douglas Corporation v. Green, 411 U.S. 792
(1973). For complainant to prevail, he must first establish a prima facie
of discrimination by presenting facts that, if unexplained, reasonably
give rise to an inference of discrimination, i.e., that a prohibited
consideration was a factor in the adverse employment action. See
McDonnell Douglas, 411 U.S. at 802; Furnco Construction Corp. v. Waters,
438 U.S. 567 (1978). The burden then shifts to the agency to articulate
a legitimate, nondiscriminatory reason for its actions. See Texas
Department of Community Affairs v. Burdine, 450 U.S. 248, 253 (1981).
Once the agency has met its burden, the complainant bears the ultimate
responsibility to persuade the fact finder by a preponderance of the
evidence that the agency acted on the basis of a prohibited reason.
See St. Mary’s Honor Center v. Hicks, 509 U.S. 502 (1993).