Fidelius Charm

[corinthum]

No: HPFGUIDX 90799

John asked:

> I have been re-reading PoA and a new thought occurred to me. DD 
> performed the Fidelius Charm right? Why wouldn't he testify to 
> clear Black's name? DD presumably would know who the secret keeper 
> is, because it is necessary to the Charm to have a secret keeper. 
> If DD can clear Snape's name by testifying why can he not clear 
> Sirius' name? DD should have testified as soon as Sirius was 
caught. 
> Why did he not? There may have been the problem of all the people 
> Peter killed, but Sirius could have explained about MWPP's 
> transformations. Surely a life sentence in Azkaban would have been 
> more than enough reason to expose his illegal transformations and 
> his friends. Sorry if this has been discussed before, if so then 
> someone please tell me how to find the previous conversation. 

Dumbledore suggested the use of the Fidelius charm, but I don't 
believe he was the one to actually cast it.  I've always assumed that 
Lily and James cast it themselves.  It's stated several times that 
only Lily, James, Sirius, and Peter knew that Peter was the Secret 
Keeper, so if a third party was needed to cast the spell, I assume 
Sirius would have been the one to do so.

The Potters told Dumbledore that they were going to use Sirius as 
their Secret Keeper, and they never told him of the later switch.  
Therefore, he had no way of knowing that Sirius was innocent.

-Corinth