Muller has pulled immunity agreements previously on the table protecting Comey :multiple DOJ sources.

Any immunity agreement that was previously on the table protecting Comey is now off the table, according to multiple
DOJ sources.
Comey’s previous deal insulated him against prosecution for his role in many controversial FBI cases and emerging scandals. However, absent a deal protecting him from Mueller’s team or a grand jury, Comey could be implicated in a number of growing probes, including:
* Leaking other government documents to third parties including the media
* Inconsistencies in testimony that rise to the level or perjury
* Any role he played in the illegal surveillance or wiretapping of Trump during the election
* Any other crimes Comey may have committed during his tenure as FBI director, including his role in quashing the Hillary Clinton email investigation.
* His role in unmasking Trump, Trump insiders and other Americans from FISA warrant intelligence
* Any violations of FBI employment ethics that would nullify pension benefits.
* Uranium One.
* Legal spillover from the investigations targeting FBI Deputy Director Andrew McCabe.
* Other cases which have not been made public.
 
youtu.be/S4ZPKfVrql0
 
 
h/t Etheric Traveler