Camille, simply say "the first step is to go to the nearest police station and file a report." (These days, the first thing you do is call 911 from your cell phone, in the U.S.) Of course I'm not familiar with all the terms used in other countries, but "offical occurence report" is not one I am familiar with.
He was arrested flagrantly - what do you mean to say by this? His arrest was spectacular? Like, he was arrested at his own wedding in the middle of taking his vows?
To pay an indemnity. - This is not a complete sentence, as you no doubt know. I'm not sure what you mean by "an indeminity."
Indemnity is a legal term, but is that how you mean it?