Not all crimes require intent. Crimes where intent is not required are called "Strict liability" crimes, for those crimes it is sufficient to prove that the accused did the thing which is forbidden, and it's entirely irrelevant (to guilt, though not necessarily to sentencing) why they did it.

Also for some crimes the intent needn't match the outcome. For example in the UK _Attempted Murder_ requires (as well as facts of an attempt) you had an intent to kill, but _Murder_ only requires that you had an intent to at least cause grave harm, the fact of death makes it murder, even if a jury believes you intended only, say, to hospitalize the victim.