NEW : U.S. Capitol Police are working with the FBI on the investigation . Comment: nontoxic ' A campaign spokesman says there were two swastikas on the package . on Thursday found a white , powdery substance and drawings of two swastikas inside an envelope , Grijalva campaign spokesman Adam Sarvana told CNN . It is the third security issue at Grijalva 's district offices this year , a spokesman says .
NEW : U.S. Capitol Police are working with the FBI on the investigation . Comment: nontoxic ' A campaign spokesman says there were two swastikas on the package . It is the third security issue at Grijalva 's district offices this year , a spokesman says .