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This case ([1991] WL 840020) demonstrates how persons investigating an alleged offence have to be careful about exploiting technicalities in law to cause the suspect to incriminate himself. This particular case, heard on appeal in the High Court, concerns a Television licence. According to s.1(1) of the Wireless telegraphy act (1949) it is an offence to ...install or use any apparatus for wireless telegraphy except under the authority of a licence in that behalf granted by the Secretary of State... Mrs Mitchell admitted that she owned a television receiver, but denied that she used it. When investigating officers called at her house, they asked her to switch the receiver on, which she did. This was taken as a 'use' within the terms of the Act, and she was convicted. On appeal, however, the High Court decided that the only demonstrable 'use' of the television was at the express instigation of the investigators, and that this did not constitute use for the terms of the act. Her conviction was therefore quashed.