From a deontological perspective, how would the justification of killing a person about to commit a terrorist act be viewed?

From a deontological perspective, the morality of actions is determined by adherence to rules or duties rather than the consequences of those actions. Deontologists prioritize principles and the inherent nature of actions over outcomes. In this framework, killing is fundamentally considered wrong regardless of circumstances or potential benefits, such as saving lives. Thus, even if a person is about to commit a terrorist act, the act of killing them would still be viewed as morally wrong because it violates the duty not to kill. The focus is on the integrity of the moral law itself, rather than weighing potential consequences, which aligns with the principles of deontology.