Gunman in Brussels Jewish museum killings a lone wolf or a hitman?
Killing of trio including a Jewish couple 'likely terror attack' but other theories not ruled out
The shooting of three people at Brussels' Jewish Museum was probably a "terrorist attack", Belgian officials said, though some security experts suggested it may have been the work of a hitman rather than an anti-Semitic 'lone wolf'.
An Israeli couple and a French woman were killed in the shooting on Saturday. A Belgian man remains in critical condition and the gunman is on the run.
Police released a 30-second video clip from the museum's security cameras showing a man wearing a dark cap, sunglasses and a blue jacket entering the building, take a Kalashnikov rifle out of a bag, and shoot into a room, before calmly walking out.
A spokeswoman for the federal prosecutors said the killings were being treated as a likely terrorist attack but other possibilities were not being ruled out.
"The fact that all lines of inquiry remain open means that we have no certainty about it being a terrorist attack but it seems very likely to us," spokeswoman Wenke Roggen said. "The footage shows a person who seems cold blooded and determined."
Some security experts said the way the assailant carried out the killings suggested planning and execution by a specialist.
Edwin Bakker, professor at the Centre for Terrorism and Counterterrorism at the University of Leiden in the Netherlands, said the gunman's calm manner indicated he had experience.
He said no organisation had claimed responsibility, suggesting it was not the work of militants. "People use the word terrorism very quickly but when I saw the images I thought this is a hitman," Bakker said.
One of the Israeli victims, Emmanuel Riva, had previously worked for Nativ, a government agency that played a covert role in fostering Jewish immigration from the former Soviet Union.
Along with Israel's foreign intelligence agency, Mossad, and its domestic security equivalent, Shin Bet, the Nativ agency was under the authority of the prime minister's office.
Miriam Riva, his wife, had also worked in the prime minister's office in the past.
Friends of the couple interviewed by Israeli media said they both worked as accountants in government service.
Other analysts dismissed the notion that this was some kind of contract killing or settling of scores among intelligence services, saying the daylight attack indicated it was more likely a random attack on Jews.
Rolf Tophoven, an analyst at the Institute of Crisis Prevention in Essen, Germany, drew a parallel with the killing of two US airmen at Frankfurt Airport in 2011 by a young Kosovo Albanian Muslim who had been radicalised online.
"We call this leaderless jihad, people who radicalise themselves on the internet," said Tophoven, laying out the "lone wolf" scenario. "It would be the story of the autonomous terrorist whom nobody had on their radar screens, whom nobody knew."