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Overview
This page explains how police investigate a crime, collect evidence, and identify the person responsible. It also outlines what you can expect during the investigation and how police will keep you informed.
Starting the investigation
When police investigate a crime, a police officer in charge is responsible for getting the case ready. A police officer will talk to you and anyone else who knows something about the crime.
You may be asked questions more than once as investigators work to build a full picture of what happened.
Collecting evidence
The police will collect evidence to help make an arrest. This might be:
- physical evidence, such as clothes or other property
- medical evidence
- photos, CCTV footage or digital communications.
If there is enough evidence, they can make an arrest and charge a person.
You might find the investigation process slow or uncertain. Your police contact will explain what’s happening and answer any questions you may have.
Medical evidence
If you have been physically assaulted or are a victim-survivor of sexual violence, you might be asked to have a medical examination.
A medical examination can help collect evidence and make sure injuries or health concerns are treated. The examination is done by trained health professionals.
A medical examination for sexual violence(external link) matters is done by a specialist health trained professional.
Police may need to look at where the crime happened (the crime scene). It is better not to touch the area until you know if they need to look at it or not.
The police might keep hold of your property while the investigation is happening. You have the right to have your property returned as soon as possible. If your property is needed as evidence in a court case it might be a long time before police are able to return it.
You may be able to get financial assistance depending on the situation.
More information about Financial help
Identifying the offender
The police might ask you to look at photographs or attend an identification parade, also known as a police line up, to help point out the accused person.
Taking part in these processes can be distressing. You are not expected to know everything or remember every detail. Sharing what you honestly recall can help the investigation.
For more information: Advice for victims | New Zealand Police(external link)