A.B. v. Slippery Rock School District - Commonwealth Court - August 31, 2006
http://www.courts.state.pa.us/OpPosting/CWealth/out/695CD06_8-31-06.pdf
In this school expulsion case, the court (at n. 5) affirmed that the "level of proof required to establish a case" before an administrative agency or other quasi-judicial body is a preponderance of the evidence, citing Lansberry v. PUC, 578 A.2d 600 (Pa. Cmwlth. 1990).
The court also said (at n. 8 and related text) that circumstantial evidence can be used to satisfy that burden.
