What is an interrogation under caution?

Being questioned "under caution" means you are a suspect, not a witness. At the start, the investigator must tell you what you are suspected of and caution you: you are not obliged to say anything, anything you say may be used as evidence, and refraining from answering may strengthen the evidence against you. Someone questioned "as a witness" and cautioned only midway is entitled to challenge what was said before the caution.

Before the interrogation you have the right to consult a lawyer, and the investigator must tell you so and document it. The lawyer does not sit in the room with you, but you may ask for a break to consult again. A confession taken in breach of the right to counsel may be excluded (the Yissacharov ruling). The interrogation is conducted in a language you understand, and for offences carrying 10 years' imprisonment or more it is video-recorded in full.

The summons comes by phone or letter, sometimes without saying what the suspicion is. No law compels you to appear for a phone summons, but a concern that you will not show up is grounds for arrest without a warrant (Arrests Law, section 23). The central decision is what to say and what not to say, and it is made beforehand, not in the room.

What a lawyer does: contacts the investigator, clarifies the suspicion, arranges a convenient date and asks for a postponement if needed; holds a confidential preparation meeting with you; stays reachable by phone during the interrogation; and afterwards follows the file and handles the return of seized property.

Source in law: Criminal Procedure (Enforcement Powers – Arrests) Law, 5756-1996, section 34; Criminal Procedure (Interrogation of Suspects) Law, 5762-2002, sections 2, 4 and 7; Criminal Appeal 5121/98 Yissacharov