When interviewing the witness, the investigator will portray no judgment or acceptance towards what the witness is saying. The witness may be under severe emotional stress or afraid to speak openly, making the interview a real challenge. OSHA advises that investigators interview witnesses as soon as possible and do this alone, not in a group, to ensure that accounts are accurate and truthful. The interview itself can occur at the scene of the accident, to better establish the positions of each person involved, or away from the scene, where the witness may feel more comfortable and secure.

Investigators will inform witnesses that the primary purpose for taking their statements is to prevent future accidents. However, witnesses need to know that confidentiality is not assured.