Definition: In this task, a passage will be given and the goal is to identify an event from the passage. An event is defined as a single word representing something that happened, is happening, or may happen. An event can be factual or hypothetical, positive or negative, certain or uncertain. While most events are based on verbs, an event can also be based on a noun (ex. storm, snow, rainfall) or a copula verb (is, was, been, etc.). The event must not be a pronoun or an adjective. For noun events with multiple words, use the last word in the phrase as event.
Input: Passage: German police subsequently found traces of the polonium in Hamburg, where one of the contacts, Dmitry Kovtun, stopped on his way from Moscow to London for the meeting. Hamburg prosecutors have opened a criminal investigation against Kovtun for apparently bringing the radioactive substance into the country from Russia and said they considered him "more a perpetrator than a victim."

stopped