Key questions about MH17 charges

The announcement Wednesday of charges over the downing of flight MH17 has raised important questions, from whether the suspects will ever appear in court to why senior Russians are not prosecuted.

Here are three of the main issues:

What are the suspects accused of?

Each suspect faces two criminal charges: firstly "crashing flight MH17, resulting in the death of all passengers,"; and secondly "the murder of the 298 occupants of flight MH17".

Investigators admitted the three Russians and one Ukrainian charged had "not pushed the button themselves" on the BUK missile that brought down the Malaysia Airlines plane five years ago.

But Dutch prosecutor Fred Westerbeke told a press conference it was enough that the four had "closely cooperated to obtain the BUK and put it in position on the launch site with the goal to shoot a plane."

He added: "In Dutch criminal law, persons who are not present themselves during the implementation of a crime but play an important organising role are just as punishable as the persons who actually committed the crime."

Why were there no other charges?

Ahead of Wednesday's announcement, expectations ran high that Russian top brass would be among those charged, based on a statement by a Ukrainian minister and reports in Dutch media.

Instead, all four suspects turned out to be senior figures in the separatist Donetsk People's Republic in eastern Ukraine, rather than the Russian military itself.

Dutch police chief Wilbert Paulissen said Wednesday the "investigation towards prosecution of other suspects will proceed".

Investigators were hunting the crew that operated the BUK missile system, believed to be about four people, "and people who formed the link in the Russian chain of command."

Prosecutor Westerbeke said they simply did not have enough evidence yet to secure criminal convictions of other suspects.

"We want to go as far as we can get," he said, appealing for more witnesses.

Will the suspects ever appear in court?

Investigators admitted it was unlikely the suspects would appear in the dock in the Netherlands.

The Russian and Ukrainian constitutions forbid extradition of their nationals to any other country, Westerbeke said.

"I am a realist, meaning that I don't think the odds are now on our side", he said, adding Russia had so far refused to cooperate.

"That is a slap in the face to the bereaved, and I call out to them (Russia) to start cooperating," he added.

Under Dutch law, however, the men can be tried in their absence, meaning "the criminal trial will take place even when the suspects choose not to be present."

The trial is due to start on March 9, 2020 at a high-security court in Schiphol -- close to the airport where the doomed flight took off.