Police clocked P’s vehicle traveling at 73 miles per hour on a road with a 55-mile-per-hour speed limit. The deputy activated his blue flashing lights and D ignored them and sped away, initiating a chase down what is in most portions a two-lane road, at speeds exceeding 85 miles per hour. D heard the radio communication and joined the pursuit along with other officers. P pulled into the parking lot of a shopping center and evaded a trap by making a sharp turn, colliding with D’s police car, exiting the parking lot, and speeding off once again down a two-lane highway. D decided to attempt to terminate the episode by employing a PIT maneuver. D got permission but applied his push bumper to the rear of D’s vehicle. D lost control, left the roadway, ran down an embankment, overturned, and crashed. D was rendered a quadriplegic. D sued under 42 U. S. C. §1983, alleging, inter alia, a violation of his federal constitutional rights, viz. use of excessive force resulting in an unreasonable seizure under the Fourth Amendment. D filed a motion for summary judgment based on an assertion of qualified immunity. The District Court denied the motion. The Eleventh Circuit affirmed. The Supreme Court granted certiorari.