(Portland, OR) -- Portland Police conducted a yearlong investigation into an illegal drug operation and arrested nine people. It started with a tip about a house where it appeared drugs were being sold. In June, police searched the house and seized 19 guns, body armor, ammunition, illegal drugs, a stolen vehicle and 10-thousand dollars in cash. Four people were arrested. This month, police served several other warrants seizing 12 guns, drugs and two stolen vehicles. Five people were arrested. The FBI helped with the investigation.