Moreover, they started with the reporter, since he seemed to be the leader of the group (e.g. he was the one doing the talking).
The wording there with him seeming to be the leader of the group sounds like an anthropologist finding a completely unknown tribe of people. At any time, the police could've just used their words, instead of being silent, surrounding the entire group, then suddenly arresting one person and waiting a full 2 minutes (precisely two minutes) before simultaneously arresting the others.