Final answer:
The question pertains to the time frame for an investigation to begin after a complaint, which is likely governed by an organization's internal policies or employment law, not covered by the provided references to criminal law or historical legislation.
Step-by-step explanation:
The question raises a specific procedural issue related to internal or administrative investigations within an organization or institution, rather than a criminal proceeding covered by constitutional rights. The student is asking about the guidelines for the initiation of an investigation after a complaint has been submitted. This is a question that would likely fall under policies specific to an organization or under employment law, rather than criminal law. Unfortunately, without specific context or a reference to an organizational policy or legal statute, providing a detailed time frame for when an investigation must commence is not possible. It is essential that the investigating officer is unbiased, hence being senior to both the complainant and the alleged offender helps ensure impartiality.
The references provided, such as the accused's right to a speedy trial and the historical context of the Lex Julia permitting the detention of witnesses for a certain period, do not directly answer the student's question regarding the timeframe for commencing investigations. However, they do illustrate the principle of ensuring justice is carried out expeditiously and fairly, which may indirectly inform organizational policies aimed at addressing complaints and allegations in a timely and just manner.