Can departments hire student employees and limited employees and allow them to begin working in sensitive positions before criminal background check results are completed?

Since both student employees and limited employees can be terminated at will if the criminal background check reveals relevant criminal convictions, a department may at their discretion choose to let such employees begin working in some positions before completion of the background check. It depends upon the kinds of sensitive duties the employee would perform and the potential consequences of criminal behavior. For example:

For a position that has been designated sensitive because of access to cash, the department may carefully weigh the University's business need against risk management considerations and decide that a student or limited employee whose job duties would include, e.g., part-time operation of a cash register in a low-volume gift-shop operation does not pose a significant financial risk of theft or embezzlement, and can allow the employee to begin performing the duties before the criminal background check results have been received.
For a position that has been designated sensitive because of duties involving contact with children, the potential consequences of even a single act that caused harm to children would outweigh any business need considerations, and the individual should not be allowed to start working in the job before being cleared
For a position that has been designated sensitive because of access to keys, the decision of when a student or limited employee can begin work should take into account the nature of the theft or harm that could result from misuse of the keys. For instance, if the employee would possess keys to an office supplies storeroom, the department may consider that this does not represent a risk of significant theft. But if the employee possesses keys to dormitory rooms or to laboratories with hazardous materials, the consequences of misuse of the keys may represent too great a risk of harm.