the question of what a reasonable jury could determine regarding reasonableness — is an issue that we consider de novo. See, e.g., Altman v. City of High Point, 330 F.3d 194, 204-07 (4th Cir.2003) (reversing district court order denying qualified immunity and concluding that officers’ actions were reasonable); Elliott, 99 F.3d at 644 (explaining that in reviewing the denial of summary judgment based on qualified immunity, although we may not review a determination by the district court that the forecasted evidence gives rise to a reasonable infer ’s expert’s opinion that Appellants' actions were unconstitutional. "Opinions, be they expert or lay, are only as good as the evidence upon which they are based.” Id. at 1280 n. 11; cf. Washington v. United States, 214 F.2d 33, r.1991) (<HOLDING>). 10 . It is important to note that Pittman
recognizing that deadly force is only justified where a suspect poses an immediate threat holding that use of deadly force was justified when suspect in vehicle repeatedly refused orders to raise his hands and the officer perceived that he was holding something holding that an officer may use deadly force when a fleeing suspect threatens the officer with a weapon holding that use of deadly force was justified against a suspect when officer forced to make a splitsecond decision relied on his reasonable belief that another officer had seen a gun in the suspects hands even though the suspects hands were handcuffed in front of him and the defendant officer never saw a weapon holding that expert testimony on what constitutes deadly physical force and whether the use of force was justified should have been excluded