Violent crimes committed by asylum seekers have been reported as "other" in a Dutch government document.
Leader Thierry Baudet has been advocating "Nexit" but might have modified his views recently in light of the Brexit quagmire.
The suspect is believed to have escaped the site of the tram shooting in Utrecht by car.
The Dutch counter-terrorism police appeared to be preparing to raid a house located near the shooting site.
Dutch Prime Minister Mark Rutte has warned that the Netherlands and some other EU member states would not go along