The white Minnesota police officer who fatally shot Daunte Wright, a 20-year-old Black man, after appearing to mistake her handgun for her Taser will be charged with second-degree manslaughter on Wednesday, a prosecutor said, following three nights of protests over the killing. The charges against the officer, Kimberly A. Potter, come a day after she and the police chief both resigned from the Brooklyn Center Police Department. Hundreds of people have faced off with the police in Brooklyn Center each night since Mr. Wright’s death, and residents across the region are preparing for a verdict next week in the trial of Derek Chauvin, the former Minneapolis officer charged with murdering George Floyd.