A JW mock trial needs
- Two witnesses to the same event
- OR two witnesses to separate events of the same 'sin' (e.g. 2 JW both saw him smoking but at different occasions, or 2 victims that claim he touched their underage genitals, etc.)
- OR a confession from the sinner to 2 elders*
- OR two witnesses that personally heard a confession from the 'sinner' (e.g. he told his two best friends he shagged his GF, doesn't confess to elders himself, but his treacherous friends do tell on him)
Note that this information gathering is done before a JC is even started. A JC is only started when it's clear the 'sin' has been commited. During the JC they'll only verify the details of the case in order to verify how bad the perpetrator is and thus how many time he has to say a hail-Mary...erm I mean how long he'll be put on restrictions. Only in rare cases can an accused (who didn't confess) show the JC he actually didn't do whatever he's accused of. And in that case he might still be reproved for contempt of authority.
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*) These elders will preferably then not be part of the JC, but will function as witnesses to the prosecution, just as the witnesses in point 4