Los Angeles County dropped criminal charges against the top executive of an elections technology company on Wednesday, bringing to an abrupt end an unusual case that became the focus of election deniers nationwide. The district attorney’s office said in a statement that it had dropped the case against the executive, Eugene Yu, because of concerns about the “pace of the investigation” and the “potential bias in the presentation” of evidence in the case. The office said the county had assembled a new team to “determine whether any criminal activity occurred.” The prosecutors did not respond to questions about the decision....