I'm going to call the cops
Why are you calling the cops?
I need to file a report about what happened last night.
If something serious happened then you definitely should call the cops. However, make sure it's important so that you are not wasting the time of the cops. They are busy so it's best to sort out minor issues on your own if possible.
I know. I'm not trying to waste their time.
Then you should by all means call them! I hope whatever happened is not too serious and they are able to help you through it.