Pennsylvania Statutes Title 42 Pa.C.S.A. Judiciary and Judicial Procedure § 5941. Persons who may be compelled to testify

(a) General rule.--Except defendants actually upon trial in a criminal proceeding, any competent witness may be compelled to testify in any matter, civil or criminal; but he may not be compelled to answer any question which, in the opinion of the trial judge, would tend to incriminate him; nor may the neglect or refusal of any defendant, actually upon trial in a criminal proceeding, to offer himself as a witness, be treated as creating any presumption against him, or be adversely referred to by court or counsel during the trial.

(b) Judgment debtor.--A judgment debtor may be compelled to answer all pertinent questions at any examination concerning his property, but he shall not be prosecuted, or subjected to any penalty or forfeiture, for or on account of any transaction, matter or thing concerning which he may so testify or produce evidence, documentary or otherwise, except for perjury in giving such testimony.