Associated Press: South Dakota's U.S. attorney to resign

The U.S. attorney for South Dakota plans to resign and open an office in Sioux Falls for a private law firm.

Multiple sources with knowledge of the situation who were not authorized to discuss it confirmed to The Associated Press that Brendan Johnson will announce his resignation Wednesday at a news conference.

He plans to open an office for Minneapolis-based Robins Kaplan, which also hired North Dakota's U.S. attorney, Tim Purdon, to practice in Bismarck, according to the sources.

Some Democrats had hoped Johnson would have run for the Senate seat vacated in January when his father, U.S. Sen. Tim Johnson, retired. Republican Mike Rounds won that race.

Before becoming U.S. attorney in 2009, Johnson was a federal law clerk, deputy state's attorney and partner for a private law firm in Sioux Falls.

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