39 CFR §962.5

1. (a)A hearing under this part will be conducted by the Presiding Officer to determine:
   1. (1)Whether the Respondent is liable under 31 U.S.C. 3802; and
   2. (2)The amount of any civil penalty or assessment to be imposed if the Respondent is found liable under 31 U.S.C. 3802.
2. (b)The Postal Service must prove its case against a Respondent by a preponderance of the evidence.
3. (c)The parties may offer at a hearing on the merits relevant evidence that is admissible under the Federal Rules of Evidence, subject, however, to the sound discretion of the Presiding Officer in supervising the extent and manner of presentation of the evidence. In general, admissibility will hinge on relevancy and materiality. Relevant evidence, however, may be excluded if its probative value is outweighed by the danger of unfair prejudice, or by considerations of undue delay, waste of time, or needless presentation of cumulative evidence.