Qualified immunity is a legal doctrine that protects government officials, including police officers, from being held personally liable for constitutional violations, as long as their actions did not violate "clearly established" law. This means that if a government official acts in a way that a reasonable person would not recognize as unlawful, they may not face legal consequences. The purpose of qualified immunity is to allow officials to perform their duties without the fear of constant litigation. However, it has been a topic of debate, with critics arguing that it can shield misconduct, while supporters believe it is necessary to protect officials from frivolous lawsuits.