Police wanted to keep supermarket bombing secret

The police had wanted to keep the birthday card filled with explosive dust that was delivered to the Jumbo store in Zwolle last month a secret. They only released the information after the local residents became unsettled when noticing the extra security measures taken at the Jumbo stores in Zwolle.

Rob Vos, who is leading the investigation into the Jumbo extortionist on behalf of the Noord-Nederland police, said this to the AD.

"We indeed did not intend to reveal that there were explosives in the birthday card", Vos said. "For us it is always a balance between openness, investigative interest and the safety of, in this case, the customers and staff of Jumbo. In the interest of the investigation into the perpetrator we decided not to publicly communicate about the explosive that was delivered to the Jumbo in Zwolle."

On Thursday the police released a large amount of information on this case in the hopes that the public can help them with their investigation. So far more than a hundred people have responded, according to the newspaper. A spokesperson for the police said that they are very satisfied with the response. "Now we have to examine whether there is new and useful information."

A total of 30 detectives are working on this case. Two explosives have been planted at Jumbo stores in Groningen, one of them actually exploded, and the Jumbo store in Zwolle received the birthday card containing an explosive substance. The perpetrator is demanding that an amount of bitcoins be paid over to him. The police assume that the culprit is a man between the ages of 20 and 40 years and living in the city of Groningen. They believe he is an "intelligent" man with knowledge of explosives, electronics and computer systems.