If you have carefully drafted a criminal complaint, submitted it to the police, and attached all the evidence without omission, is it now simply a matter of waiting since the case has been handed over to an investigator? In actual investigations, this is often not the case.

In the 'complainant investigation' that takes place after the complaint is submitted, the investigator re-examines the structure of the case and asks about matters that are difficult to know from the complaint alone. If a well-written complaint is the starting point of an investigation, the complainant investigation is akin to the process of checking the actual road while holding that map.

■ Legal Basis for the Complainant Investigation

Article 22 of the current Police Investigation Rules stipulates that even when a complaint is received in writing, if additional statements are needed, a supplementary written statement must be submitted or additional testimony heard. Article 39 of the same rules also allows statements from persons other than the suspect to be recorded in a statement transcript. This means that filing a complaint does not end one's testimony; rather, it is from that point that the process of concretely aligning the case with the investigator begins.

■ Preparation Before the Investigation — Reread the Complaint First

The first thing to do before the investigation is to reread the complaint you filed. In particular, you should check the framework of the case, such as the dates and amounts stated in the criminal facts, what the other party said, and the circumstances under which the money moved.

This is even more important if a lawyer or someone else drafted the complaint. If you answer as if hearing the key contents of the complaint for the first time, even though it is your own case, the flow of your testimony may falter.

However, there is no need to memorize the sentences of the complaint in full. Rather, memorizing the sentences verbatim may cause discrepancies with your actual memory and expression.

■ Testimony Tips — Distinguish the Source of Your Memory When Speaking

In the investigation, it is important to distinguish between 'facts I directly remember,' 'facts I confirmed by looking at bank accounts or KakaoTalk,' and 'what I heard from others.' Above all, you must not miss facts connected to the elements of the crime.

In a fraud case, it is not enough to simply say 'I did not get my money back.' The key is what the other party said before you sent the money, which of those statements differed from the truth, and whether you sent the money because you believed those statements. Ultimately, the complainant investigation is also a process of verifying whether such criminal facts match actual experience and evidence.

■ Reviewing the Statement Transcript — Always Before Signing

At the end of the investigation, it is advisable to slowly read through the prepared statement transcript. You should check whether the dates and amounts are correct, and whether content you did not affirm has been written with expressions such as 'definitely,' 'not at all,' or 'from the beginning.' If anything differs from what you said or is missing, it must be corrected before signing.

■ The Complainant Investigation Is Not a 'Memory Test'

The complainant investigation is neither a memory test nor a time for reading the complaint aloud. It is a process of accurately conveying the structure of the case to the investigator and verifying whether the criminal facts and evidence stated in the complaint match actual experience.

Filing a complaint does not end the investigation. If a properly written complaint sets the direction of the investigation, the complainant investigation is the first verification step that keeps that direction from going astray.