What is the test for determining whether racial animus has influenced the sentencing or sentencing of a defendant?

United States v. Redondo-Lemos, 955 F.2d 1296 (9th Cir.1992), establishes a procedure for inquiring into whether racial animus has influenced the government's prosecuting or sentencing decisions. The first step in the analysis requires the defendant to make a prima facie case. The district court may, under its supervisory powers and its duty to safeguard the constitutional rights of defendants, raise the issue of racial discrimination sua sponte based on "its own day-to-day observations." Id. at 1302. Such an observation may establish a prima facie case. Id. In this case, the district judge, relying on his day-to-day observations, expressed concern that the defendant may have been the victim of a discriminatory decision not to file a motion to depart downward.