A federal jury has convicted a former Arkansas police officer on extortion- and drug-related charges but found her not guilty on a money-laundering accusation. Former Helena-West Helena police officer Marlene Kalb was convicted Friday in Little Rock. She pleaded not guilty to all charges and testified in her own defense Wednesday. Jurors had deliberated since Thursday. Kalb was indicted last year after an investigation called "Operation Delta Blues" focused on alleged corruption and drug trafficking in eastern Arkansas. Four former law enforcement officers pleaded guilty to various charges. Police said Kalb twice accepted money to protect drug shipments.