Today at 2pm Eastern, the reporting team who produced our three-part anthrax investigation will answer your questions about the stories and whether Bruce Ivins is really the man responsible for the attacks.

ProPublica managing editor Stephen Engelberg, along with FRONTLINE producer Mike Wiser and McClatchy investigative reporter Greg Gordon will host the chat. Their anthrax series raised doubts about whether Ivins could have produced the deadly anthrax and whether the scientific methods of identifying Ivins were sound. They also revealed that the FBI withheld information about the anthrax samples that Ivins gave them that did not match the ones used in the mailings.

If you would like to pose a question to the reporters, submit it in the chat box below and come back at 2pm to see their answer.