Amsterdam—Dutch prosecutors on Wednesday demanded life sentences for three Russians and a Ukrainian charged with murder over the shooting down of a passenger jet over Ukraine in 2014. They said the defendants, who are all at large, helped supply a missile system that Russian-backed separatists used to fire a rocket at Malaysia Airlines flight MH17. All 298 people on board were killed. Prosecutor Manon Ridderbeks demanded life terms for all four, named as Igor Girkin, Sergey Dubinsky, Oleg Pulatov, and Leonid Kharchenko. Most of the victims were Dutch nationals. The Dutch government holds Russia responsible. Authorities in Moscow deny involvement. Outside the courtroom Piet Ploeg, who lost his brother, nephew, and sister-in-law in the crash, said he had waited a long time to hear the prosecution makes its recommendation. “It’s a relief that the prosecutors demanded the maximum sentence,” he told reporters. Even if the four men were never jailed, …