There are some types of employment where it will be essential to know whether a potential employee has a criminal record. Examples where information is needed:
For anyone working with children it is important to know whether they have any criminal convictions relating to violence or crimes against children.
Where the potential employee will be trusted with valuable property or money, it may be essential to know if that person has ever been convicted of any crime involving fraud or dishonesty.
Where it is essential that the employee holds a motor vehicle licence, it may be important to know whether they have been convicted of any serious motor traffic offences.