1. The order in which you collect evidence is important, although how you investigate and collect evidence will depend on the individual circumstances of your case.
2. The stages of collecting evidence are:
3. If you are investigating an incident, you should identify and obtain evidence from the "witnesses of fact" (i.e. those able to give factual information about what actually occurred, usual work systems and relevant employment issues etc). This will normally be done by taking a statement.
4. Once you have obtained evidence from the witnesses of fact, you should then seek to identify the underlying causes of the suspected breach(es) by seeking further information. This may involve taking statements from people who hold more senior positions in the organisation under investigation who may not have witnessed the incident. You should avoid seeking information from people who you suspect may have committed an offence as an individual under HSWA and/or regulations, although you may consider an interview under caution. The contents of written documents, assessments, procedures, policies etc may help to inform you as to who may, or may not, be a suspect.
5. The final stage of the investigation will usually be to speak to those people suspected of having committed an offence. This should be a formal interview under caution (Police and Criminal Evidence Act –'PACE interview').
6. Where a person is asked questions about their suspected involvement in a criminal offence, the questioning should always be in the form of a formal interview under caution. This will include interviewing a nominated representative of a company where the company is suspected of committing an offence. The circumstances when you should interview under caution are considered in more detail later in this section under "The Questioning of Suspects".
7. It will usually be appropriate to conduct an interview under caution at the end of your investigation, although there may be rare cases where the interview should be conducted at an earlier stage.
8. You should not forget that, at any stage in your investigation, you may need to go back to witnesses you interviewed earlier and put to them documents or comments that you have received subsequently.
9. Information obtained in the course of an interview under caution (i.e. following the rules of PACE) is only admissible as evidence against the interviewee in the case of an individual, or the company in the case where a representative of the company in interviewed.
10. Therefore, if a person who you interviewed under caution ceases to be a suspect and you wish to rely on their evidence, you will need to go back and obtain the information in an admissible form, i.e. a a statement under s-9 CJA (see Types of Witness Statements.
11. Alternatively, you may draft a statement from the content of the interview under caution and then ask the individual to sign the statement.
12. In either case you should make it clear to the witness that they can, under these circumstances, add to their statement if they wish, it is not restricted to what they said when interviewed under caution.