The relative pronoun and the verb in the following sentence cannot be removed. Why? Daily Mail says: A soldier who was almost killed in Afghanistan is vowing to return to Army service despite his serious injuries. When who was is omitted, the relative clause who was almost killed is reduced to a past participle clause almost killed. I think it still makes sense to me, though. A soldier almost killed in Afghanistan is vowing to return to Army service despite his serious injuries. The following sentences are in a similar construction and who was killed is reduced to killed. Is there an exception to the rule? Shields Gazette says: A soldier almost killed in a horrific rocket attack in Afghanistan is mentally and physically preparing himself for life as one of the rarest bionic men in history. KMSP-TV says: A soldier killed in Afghanistan when a man in an Afghan uniform fired on NATO troops was an American, a US defense official said Thursday. WBRZ says: A soldier killed in Afghanistan returned home for the last time Tuesday morning.