A father and son were charged with conspiring to threaten Rep. Bart Stupak (D-Mich.) and his family, The Associated Press reported Monday night.

The charges stem from an FBI investigation of a letter threatening to “paint” a bridge with the blood of Stupak and his family in retaliation for the Member’s vote in March to pass the health care overhaul.

The suspects are Russell Hesch, 73, of West Branch, Mich., and David Hesch, 50, of Loveland, Colo., the AP reported, citing federal prosecutors.

Robert Dunn, the court-appointed attorney for Russell Hesch, told the AP that his client is “absolutely not guilty.”