A series of scandals have been linked to Ms. Warren, who is seeking her third term as the mayor of Rochester, a small city just south of Lake Ontario. In the summer of 2020, the city was rocked by revelations of an apparent cover-up of the death of Daniel Prude, a Black man who died in police custody, which led to the firing of its police chief and censure of top officials. In the fall, Ms. Warren was indicted by county prosecutors on campaign finance charges for financial fraud during her 2017 re-election campaign. She has pleaded not guilty. In May 2021, her husband, Timothy Granison, 42, was accused of being part of a midlevel cocaine trafficking ring and charged on Thursday with drug and gun possession in what prosecutors said was the culmination of a seven-month-long investigation. Mr. Granison’s arrest, and the discovery of 31 grams of powder in his possession that the police believe is cocaine — as well as a semiautomatic rifle and an unregistered handgun in Ms. Warren’s home — threatened to once again upend Ms. Warren’s re-election campaign.