LITTLE ROCK A former Marvell police officer nabbed in a joint drug and public corruption sweep of eastern Arkansas pleaded guilty to federal extortion and money laundering charges Thursday, officials said.

LITTLE ROCK A former Marvell police officer nabbed in a joint drug and public corruption sweep of eastern Arkansas pleaded guilty to federal extortion and money laundering charges Thursday, officials said.

Robert Wahls was among 70 people indicted last year in the investigation known as Operation Delta Blues. Wahls entered his plea in U.S. District Court.

As part of the agreement, federal prosecutors dropped other charges filed against him in the probe. The agreement also calls for Wahls serve 24 months in prison. He is to be formally sentenced May 30.