Talking Points Memo:

But the news out of Sacramento today may have a bigger ultimate effect in stoking the story. The Acting US Attorney there, Lawrence Brown, confirmed to the Sacramento Bee that the FBI is probing obstruction of justice allegations made by a former executive of St. HOPE, the local non-profit, formerly led by Johnson, that Walpin had been looking into.
Rick Maya, who officially quit last week as St. HOPE’s executive director, claimed in a resignation letter written in April that a member of the St. HOPE’s board deleted Johnson’s emails during Walpin’s investigation into the misuse of funds at the non-profit.
Brown’s office now says it has asked the FBI to look into that allegation.

So the FBI has an active investigation into the same non-profit Walpin was probing at the time of his dismissal. Hmm. TPM has the rundown on more interesting developments as well.