View source for Manhunt: Herne Police Pursue Child-Murderer

{{Use Cases
|Use Cases Category=Real-world
|Year=2017
|Location=Herne, Germany
|Event type=Terror
|Scale=County
|SM event detection time=More than 3 days
|Description=Law enforcement in Herne had to handle the case of a child-murderer who was on the run for several days (killing a second person) and who kept the afraid public by posting further threats online.
|Type=Crowdsourcing, Social Media
|Disaster Management Phase=During
|Long description=On March 6th, 2017, a 19-year-old German from Herne (North Rhine-Westphalia) lured his 9-year-old neighbor into the basement, where he stabbed him brutally 58 times. He shared pictures of his act and the bloody scene via WhatsApp to friends, which were subsequently also circulating via the website 4Chan. Thereupon, users called to alert the police. The perpetrator then fled to a 22-year-old former schoolmate, who threatened to alert the police, whereupon the perpetrator also stabbed him with 62 knife stabs the following day. The perpetrator kept hiding in his schoolmate’s apartment for the next three days but also continued to be present in online fora (posting more pictures, making false or intentionally misleading claims and announcing further murders). This in turn resulted in great fear and insecurity in the area.
The police launched a large-scale manhunt for the perpetrator which also included asking for the support from the public via social media, among other channels. This triggered massive reactions: more than 1400 tips reached the police. Witnesses from various cities in North Rhine-Westphalia testified to having seen the perpetrator, whereupon the police moved out with a large contingent. However, the suspicion was not confirmed in any of the cases and did not contribute to the advances of the investigation. In remains unclear to date how many of those accounts were from people how wrongfully identified someone as the attacker but had the actual intention to assist the police and how many were deliberate hoaxes.
On the evening of March 9, the murderer finally left the apartment and tuned himself in to the police at a fast-food restaurant. He confessed that he had set his schoolmate’s apartment on fire. While extinguishing the fire, the fire department found the body of the second victim. 
The crisis communication during this incident was extremely challenging for the local law enforcement team because this was the first time in Germany, such a severe crime was more or less taking place in real-time on the internet over the course of several days. 
Besides the false eyewitness account, a massive amount of false information circulated online misleading the investigation. A letter was for instance identified as (potentially) authentic material from the perpetrator whereupon the police launched a public search for a dog which was completely unaffiliated with the crime. The real perpetrator on the other hand posted an actual photo of his second victim but with the wrongful claim that he had just killed an adult woman and would kill the daughter next.
|Use cases thematic=Collecting and Analysing Information from SMCS, Ensuring Credible Information, Making Information Accessible, Mobilising Citizens
|Limitations=The authorities had difficulties grasping some unfortunate aspects of the internet culture and understanding dynamics on image boards such as 4chan. They were rather unequipped to handle such massive amounts of false information and tell authentic volunteer helpers apart from pranksters.
|Additional links=https://www.sueddeutsche.de/panorama/doppelmord-in-herne-mehr-ging-ja-nicht-1.3848266, https://www.sueddeutsche.de/panorama/doppelmord-in-herne-prozess-um-marcel-h-getoetet-in-dem-streben-einen-menschen-sterben-zu-sehen-1.3658897, https://www.welt.de/vermischtes/article162727256/Hier-wird-Marcel-H-festgenommen.html, https://www.faz.net/aktuell/gesellschaft/kriminalitaet/ueber-die-groessten-grausamkeiten-spricht-marcel-h-im-plauderton-15388292.html
}}