Sentence:  The arrests, in morning raids in California, Florida and New York capped an investigation by San Francisco police into the murder of Sgt. John V. Young, who was killed by a shotgun at a desk in the Ingleside <WSD>stationhouse</WSD> on Aug. 29, 1971. 
Meaning of the word marked with <WSD> tags:  The headquarters of a police force or unit for a specific district; a police station.