Rambam, Hilchos Eidus, Chapter 12

Chapter 12: the invalidation and subsequent validation process of a Rasha

Halacha 1: Must the transgressor be previously warned to be invalidated as a witness

• The testimony needed to invalidate a person due to him being a Rasha: A person becomes invalid for testimony the moment two witnesses testify that he transgressed an invalidating sin. This applies even if he was not warned beforehand, and hence he is therefore not liable for lashes.
• Publicly known transgressions versus unknown transgressions: The above, however, only applies for publicly known transgressions, however, transgressions that people are not aware of their existence, then he is only invalidated if the witnesses warned him prior to him transgressing. The same applies for any transgression in which it is possible that the transgressor is doing it without knowledge of the prohibition.
• Examples: For example, if he swore falsely, or stole, or ate meat that was not slaughtered, that he is automatically invalidated with testimony of his actions despite not being previously worn.
• Tying knots on Shabbos: However, if he was seen tying or untying a knot on Shabbos, then he is not invalidated unless he was warned of the prohibition prior to his transgression being the majority of people don’t know that it is forbidden.
• Doing work on Shabbos or holidays: Likewise, if he was seen doing work on Shabbos or holidays, then he must be warned that today is Shabbos or the holiday, as he may have forgotten.
• Gamblers and tax collectors: Likewise, if he was seen gambling or collecting taxes in a forbidden way, then the witnesses must warn him that if he does so he will be invalid for testimony, as most people don’t know of these matters.
• The general rule: The general rule is that whenever the witnesses can tell that the transgressor knew of his sin and did it anyways then he is invalid even though he was not warned.

Halacha 2: Self-incrimination to invalidate one’s testimony due to being a Rasha

• A person cannot self incriminate himself to invalidate his witness status, as a person cannot consider himself a Rasha until there is testimony from two witnesses regarding his state.
• Stealing and lending money with interest: For example, if he comes to court and testifies that he stole or lent money with interest, he does not become an invalid witness.
• Eating nonkosher or forbidden relations: Likewise, if he claims that he ate nonkosher food or had forbidden relations, he does not become an invalid witness.

Halacha 3: If witnesses testify that the Rasha has repented

• If two witness testify that the transgressor has repented, or has received lashes for his transgression, then returns to being a valid witness.
• A contradiction between witnesses: If two witnesses testify that he transgressed a sin and another two witnesses testify that he did not, then he is considered questionably invalid.

Halacha 4: One who received lashes for his transgression

• Whoever has received lashes for his transgression returns to being invalid witness.
• This applies even if the person did not repent.
• A thief will return the stolen items: A thief who returns the stolen items does not return to being a valid witness until he repents.

Halacha 5: Repentance for one who loans money with interest

• A person who loaned money with interest is only considered to have repented when he tears his loan documents, and proclaims that he will no longer lend with interest even to Gentiles.

Halacha 6: Repentance for one who gambles

• A person who gambles is considered to have repented when he breaks his gambling dice and resolves to not gamble even not for the sake of money.

Halacha 7: Repentance for one who flies a flock of doves

• One who flies a flock of doves for the sake of attracting other people’s doves, is considered to have repented when he breaks his trapping mechanisms and resolves to not fly a flock of doves even in the desert.

Halacha 8: Repentance for one who sells Shemita produce

• One who sells Shemita produce is considered to have repented when he is checked out by the next Shemita, and writes that he has gathered a certain amount of Shemita produce and is giving it out to the poor.

Halacha 9: Repentance for one who swears falsely

• A person who swore falsely is considered to have repented when he approaches a court and tells them that he has lied during one of his oaths, or alternatively chooses to pay a hefty amount to the defendant rather than take an oath to exempt himself from payment.
• Repentance for a butcher: A butcher who has sold nonkosher meat is invalid for testimony until it is evident that he has repented, in which case he is to then wear black clothing and move to a place that nobody knows him and return a lost object of hefty value to its owners, or accept the hefty loss of an animal that he slaughtered and discovered to be invalid.

Halacha 10: Repentance for one who testified falsely

• One who testified falsely is considered to have repented when he moves to a place that people do not know him, and he refuses this testify falsely on behalf of substantial payment.