Utilitarianism Discussion

So an absolutist may say that murder is wrong. Full stop. But a utilitarian would say that murder is wrong, unless it provides a great deal of happiness for a great many people. So if Hitler had been murdered before he orchestrated the deaths of many millions, then this would have been a good thing., from a utilitarianist’s point of view. The main stumbling block with this philosophical stance is that people cannot often agree on what is good and thus different people try to justify different actions by claiming that it is for the ‘greater good’. And what about compassion: should we kill of people who are very sick or disabled, simply because this would ease the burden on Society as a whole?