Why is a thorough investigation important in disciplinary cases? Is it a legal requirement?

There is no statutory obligation to carry out an investigation before a disciplinary matter. However, it is the investigation process which will identify whether there are grounds to instigate disciplinary procedures.

The Labour Relations Agency’s Code of Practice on Disciplinary and Grievance procedures (as amended in April 2011) states that in relation to conduct and capability matters, the employer must establish the facts when a potential disciplinary matter arises and make necessary investigations to do so, promptly before memories of events fade. Having established the facts, the employer should decide whether to drop the matter, deal with it informally or arrange for it to be handled