In Farmer v. Brennan (1994) 511 U.S. 825, the court held that a prison official's deliberate indifference to a substantial risk of serious harm to an inmate violates the Eighth Amendment. The term "deliberate indifference" requires a showing that the official was subjectively aware of the risk: "A prison official cannot be found liable under the Eighth Amendment for denying an inmate humane conditions of confinement unless the official knows of and disregards an excessive risk to inmate health or safety; the official must both be aware of facts from which the inference could be drawn that a substantial risk of serious harm exists, and he must also draw the inference." (Farmer, supra, 511 U.S. at p. 837.) The court continued: "An official's failure to alleviate a significant risk that he should have perceived but did not, while no cause for commendation, cannot under our cases be condemned as the infliction of punishment." (Id. at p. 838.) Thus, for a prison official to be found deliberately indifferent under a failure to protect theory, the plaintiff must prove that before his or her injury: (1) the official personally actually knew of facts from which the inference could be drawn that there was a substantial risk of such injury occurring; (2) the official in fact subjectively drew such inference; (3) the official consciously or recklessly disregarded the risk. (Farmer, supra, 511 U.S. at pp. 836-840, 846-847.) "In addition, prison officials who actually knew of a substantial risk to inmate health or safety may be found free from liability if they responded reasonably to the risk, even if the harm ultimately was not averted. A prison official's duty under the Eighth Amendment is to ensure '"reasonable safety,'" , a standard that incorporates due regard for prison officials' 'unenviable task of keeping dangerous men in safe custody under humane conditions,' . Whether one puts it in terms of duty or deliberate indifference, prison officials who act reasonably cannot be found liable under the Cruel and Unusual Punishments Clause." (Id. at pp. 844-845.)