Deutsche Welle: After the Manchester attack, many media published profiles of the alleged attacker, but there were few with prominent photographs. Do the media not want to place terrorists in the spotlight, as this practice has often been criticized in the past?

Joachim Trebbe: There are various methods both in the media and among security authorities. In Manchester, authorities quickly identified the suspect but, for reasons related to the investigation, did not publish his name immediately. That changed in the course of the evening. Only then were the media able to decide whether they wanted to publish a name.

There were many variations. Some media focused on the person, in order to attribute the crime to the person. Where does that attacker come from? Does he look foreign or like he belongs to a particular ethnic group?

Media that provide structured coverage ask whether he was part of a group. Does he belong to a certain social group? To them, the individual is not in the forefront.

Of course, this has been discussed among journalists. They are trying to not create heroes; they do not want to hold up a poster of a perpetrator and inspire copycat crimes. The same goes for suicides. Not many personal details are published to avoid copycat suicides.

How has media coverage of terror attacks developed in recent years?

Journalists react strongly to certain signals. This applies to major damage and surprise. Both factors apply to terror attacks. That is why journalists react immediately: everyone wants to be the first one at the scene and to present the first insights. Everyone wants to post the first cellphone video. Timeliness has always been and still is an essential factor in determining newsworthiness. This, however, also leads to the fact that you end up talking about things you are not sure about.

Read more: Publicizing terrorism: How journalists should cover attacks

What role do social media play in this context?

Social media have added weight to the accelerator, because, of course, social media spread news much more quickly than conventional media outlets. We must learn to draw this distinction: new information - not the news - is spread by social media. Mass media outlets, however, do spread the news, and they should be subject to certain standards.

Most audiences do not understand the difference. They find out about an attack, an explosion and police measures and then they see pictures that look just like the ones journalists show us. That is a problem for journalism. On the one hand, journalists are compelled to be up-to-date; on the other hand, they must adhere to standards like correct facts, objectivity and veracity. In other words, what you find out in social media at the moment is far from what would be called the truth.

When TWA Flight 847 was hijacked by Hezbollah militants in 1985, then-British Prime Minister Margaret Thatcher said media silence would put an end to terror. Does journalism trigger more terrorism?

You could say so. But you cannot blame journalism alone because it is only a part of a system. You find the trigger in free, public communication in democratic societies. The fact that the media and everyone else have the right to inform themselves and to report what they have seen can be exploited by terrorists.

One of the goals of terrorist attacks is to shock the largest possible audience as quickly as possible. They achieve this by causing as much damage as possible. Journalism cannot be blamed for this; it is something you must accept if you want public information that is free and accessible to everyone - and enhanced through social media.

Joachim Trebbe is a professor at the Institute for Media and Communication Studies at the Freie Universität Berlin.

The interview was conducted by Michael Borgers.