If you are preoccupied, you are thinking a lot about something or someone, and so you hardly notice other things.
Tom Banbury was preoccupied with the missing Shepherd child and did not want to devote time to the new murder.
汤姆·班伯里一心专注着谢泼德家失踪的孩子,不想在新的谋杀案上花时间。