A judge declared a mistrial on Thursday in the federal case against a former Louisville police officer who fired shots in the raid that took Breonna Taylor’s life. Brett Hankison was charged with using excessive force that violated the civil rights of Taylor, her boyfriend, and her next-door neighbors when he shot 10 times through a window and a glass door during a drug warrant search of an incorrect apartment. Federal prosecutors argued earlier this week that Hankison was at fault because he was shooting blindly into Taylor’s residence, while the defense team claimed the officer was pushed into action because he heard a gun fire from inside the building. Taylor’s boyfriend, Kenneth Walker, had fired a single shot at police because he believed they were being robbed. After discussing the case for four days, the 12-member jury told U.S. District Court Judge Rebecca Grady Jennings that they could not come to a unanimous decision on either charge. WDRB reported that court security officers had even been sent to the jury room due to “elevated voices.” According to the Associated Press, the mistrial could lead to a retrial at a later date if determined appropriate by prosecutors.