Prima facie evidence is a legal term used to mean that you have enough evidence to prove something by pointing to some basic facts, but that your proof can be refuted.
An example of prima facie evidence in a case about whether a test was discriminatory would be evidence that minorities all performed significantly worse on the test than whites.
prima facie evidence
Law evidence adequate to establish a fact or raise a presumption of fact unless refuted
Origin of prima facie evidencesee prima facie