Article I, Section 6
Section 6. The Senators and Representatives shall receive a compensation for their services, to be ascertained by law, and paid out of the treasury of the United States. They shall in all cases, except treason, felony and breach of the peace, be privileged from arrest during their attendance at the session of their respective Houses, and in going to and returning from the same; and for any speech or debate in either House, they shall not be questioned in any other place.
I think you're going off half-cocked, Tom. You know I'm no fan of Congressional Republicans, and I'd assume a Louisiana politician to be guilty until proven innocent...but I do see the other side to this issue. This is likely to end up in the Supreme Court to get an interpretation of whether I.6's "privileged from arrest" applies to search and seizure as well; and how far the exception for felonies can be stretched to apply to suspicision of a felony. What's the standard of probable cause sufficient to overcome a Constitutional protection?
This is a fairly significant Constitutional question.
Note, by the way, "except...breach of the peace" was Cynthia McKinney's mistake. Reps don't get to punch out Capital cops. Sometimes Congresspeople think they have the equivalent of diplomatic immunity, but it just ain't so.