Justice Minister Soeren Pind said the men were charged with assisting Omar El-Hussein with the killing of a Jewish security guard outside Copenhagen's main synagogue on February 15 with a handgun.
Prosecutor Lise-Lotte Nilas said the men were charged with assisting someone to commit a terrorism act. She said in a statement that the charges relate to the "terror murder of Dan Uzan" and the attempted murder of two police officers posted outside the synagogue.
The four were not charged with assisting the February 14 crime.
Pind said today the trial was set to start March 10. If found guilty, the men who cannot be named under a court order, face up to six years in jail.
Defense lawyer Michael Juul Eriksen said his four clients have pleaded not guilty.
It has never been established whether El-Hussein, whose parents were Palestinian, had been radicalized, although in September 2014 prison authorities warned the Danish security agency that he was "at risk of radicalization."
The 22-year-old had served time for a stabbing on a Copenhagen commuter train before the shooting.
