A statement can be used in court at the trial. It could be produced as an exhibit and you would be subpoenaed as a witness. You would be questioned and cross-examined on your statement.
A subpoena is a court document that legally orders someone to attend court.
Anything that you say as a witness during the investigation is Crown (the prosecuting lawyer) evidence that can be used at the preliminary hearing or at the trial. This information may be disclosed to the defence lawyer (who represents the accused) if the defence requests it (and the defence will probably request it). This means that the defence can use your statements. Be careful what you say when you are emotionally distressed and are giving a statement.
For example, if you were to explain to the police why a young murder victim may have been in company that was considered undesirable, this might turn up in a defence cross-examination with the question, “May it be understood that you did not approve of your child’s friends?” You might find it uncomfortable and frustrating to have your statement thrown back at you in the witness box like this. It might make you very angry to have your statement interpreted in this way.
Suggestions
You may want to take a friend with you when you make a statement.
Stick to the facts and try not to stray from them.
Make only one statement.
Having your statement videotaped may be a good idea.
Mennonite Central Committee Canada. (2011). Getting through the maze: A guidebook for survivors of homicide.