Police officers are generally charged with the apprehension of criminals and the prevention and detection of crime, protection and assistance of the general public, and the maintenance of public order. Police officers may be sworn to an oath, and have the power to arrest people and detain them for a limited time, along with other duties and powers. Some police officers may also be trained in special duties, such as counter-terrorism, surveillance, child protection, VIP protection, civil law enforcement, and investigation techniques into major crime including fraud, rape, murder, and drug trafficking.