(Portland, OR)  --  Portland police say they've arrested a man who's accused of filming officers outside the East Precinct for months and possessing an "arsenal" of weapons and ammo.  Authorities say Eugene Crowl began filming police from his SUV in April and told an officer when he was pulled over at one point that he was a "Constitutionalist."  Officials say Crowl was arrested Sunday when it appeared he was conducting surveillance on the East Precinct building during a shift change.  Investigators say the cache of weapons and ammo was found in Crowl's Chevrolet Tahoe, and also say a number of weapons and hundreds of rounds of ammunition were found in his home.