A 43-year-old man was arrested at his home in The Dalles on Wednesday by the Mid-Columbia Narcotics Task Force.  The Dalles Police Chief Jay Waterbury says Shonn David Watson was taken into custody as officers executed a search warrant in the 800 block of Richland Court.  Waterbury adds officers seized drugs and firearms from the home.  Watson was lodged at NORCOR on charges including possession and delivery of a controlled substance within a thousand feet of a school, felon in possession of a firearm and a restricted weapon, and possession of a firearm with the serial number removed.  Waterbury said the arrest was the culmination of a lengthy investigation.