What is the penalty for falsely confessing to a crime?
Let's assume this is a false confession to one of the death penalty offenses. The case law in Deut. 19:16-21 applies to all people "bearing witness" officially (in a public trial, before a judge/jury). This includes false confessors, who are bearing witness (falsely) to their own guilt. Because the false confession is for a death penalty offense (in our hypothetical case), the penalty required in the case would ordinarily be death (the talion equivalent). But remember that the falsity of the confession must also be proven by two witnesses. Even if the false confessor recanted publicly (confessing to their original false witness), this would also have to be corroborated by another witness (e.g. someone with testimony that could directly contradict the original claim).
Confession when there is no actual crime
If there were no original death penalty crime, then the confessor may be delusional, or simply mistaken. It's possible that someone might be attempting to commit suicide by the use of the justice system. If there is no actual crime, it seems that the above case law would not apply. First, there is a question of establishing mens rea (guilty mind) according to the Biblical standards. Typically, mens rea is only established by a witnessed action between persons: the murderer "hated" the victim "in time past" (Deut. 4:42, cf. Num. 35:20). It might not be possible to do this for a single person.
Second, God's motives in commanding the death penalty for murder are:
- Retribution for an actual murder (Gen. 9:6, Num. 35:31)
- Protecting others from future criminal action by the perpetrator (Deut. 19:19)
- Deterrence of other would-be murderers (Deut. 19:20)
Punishing an attempt at murder (Deut. 19:16-21) also fulfills the latter two motives. In the case of attempted suicide, though, when there is no actual crime to which the person is confessing, none of the above motives would seem to apply. Although an attempt at suicide is (technically) an attempt at self-murder, it seems the civil government has no legal authority to punish such an attempt. In this case, there was no attempt to harm others or to pervert justice in an actual case. The person should instead be counseled/helped.
"Forced" to confess by threat to self or others
If someone perverts justice in a death penalty case, there is no defense of "duress." It seems clear that God's assignment of the mandatory death penalty in Biblical law to a crime (murder, adultery, kidnapping, rape, false witness in a death penalty case, etc.) means that that crime can never be "weighed ethically" against an alternative. For example: it is never ethically right to commit adultery in order to prevent a murder, or to murder one (innocent) person in order to prevent the death of one or more other persons.
All witness statements must be voluntary, and this includes confessions. Coerced confessions cannot be assumed to be true, therefore they are legally inadmissible. If an intentional false confession can be proven by at least two witnesses, then the false confessor would be given the penalty of the crime he confessed to, even if he acted under duress.
Mistaken confessionIn the case of a mistaken confession, the person does not have mal-intent, thus no mens rea (guilty mind). I believe the same thing could be argued about delusion.
- Apparently, this happened sometimes among the Puritans -- people would falsely confess to witchcraft in order to commit suicide. See Hansen, Witchcraft at Salem, p. 47
- A technical exception to the latter, though, would be intentionally sacrificing one's own life in an attempt to save another innocent person, but that's a different issue than what we are discussing.