This situation is impossible in real life because the existence of multiple personalities in the human body is fictional. In novels or movies, if the second personality unknowingly became the first personality, it was usually a plot setting and not a real situation in real life. If such a situation occurred in the novel, whether it constituted a crime depended on the specific circumstances of the plot. In some cases, this may be seen as fictional or deceptive behavior, but it is not usually seen as a crime. In any case, if you find yourself or someone else experiencing a similar situation, it is recommended to consult a professional for accurate help and advice.