Is the use of deadly force by a law enforcement officer to apprehend a suspect a seizure under the Fourth Amendment?

B. The use of deadly force to apprehend a suspect is a seizure under the Fourth Amendment. See Tennessee v. Garner, 471 U.S. 1, 7 (1985). Law enforcement agents may use deadly force only if they reasonably believe that killing a suspect is necessary to prevent him from causing immediate physical harm to the agents or others, or to keep him from escaping to an area where he is likely to cause physical harm in the future. Even then, deadly force may not be deployed until the suspect has been given a warning and an opportunity to surrender, unless giving a warning will materially increase the risk of bodily injury or escape. See id. at 11-12.