The chief security officer of the Senate, he preserves order in the chamber & the galleries
... sergeant at arms - The 
chief security officer of the Senate, the Sergeant at Arms and staff in the office 
help to preserve order in the Senate chamber, the Senate galleries,... [DOC] [TLE] Legislative Glossary - CONGRESSIONAL FIRE SERVICES INSTITUTE [PAR] Bills are designated with an S (for the Senate) or H.R.