>> bret: in tonight's whatever happened to segment, the investigation into who placed pipe bombs near the offices of the republican and democratic national committees in 2021. right around january 6th. correspondent david spunt tells us what we know and what we don't know tonight. >> half a million dollars. that's what the fbi might pay you if you can help them identify this person leading to the arrest and conviction. the bureau says the person, covered from head to toe, placed pipe bombs near the dnc and rnc headquarters on january 5th, 2021. the night before the capitol riot. the mystery has yet to be solved. the fbi recently telling fox news over the past three years a dedicated team of fbi agents analysts, data scientists and law enforcement partners has worked thousands of hours conducting interviews, reviewing physical and digital evidence and assessing tips from the