A 21-year-old Dutch citizen is suspected of fatally shooting the journalist, while a 35-year-old Polish national is accused of being the getaway driver.
Both men were arrested shortly after de Vries was gunned down in broad daylight on a central Amsterdam street on July 6.
They were both present for Monday’s preliminary hearing at Amsterdam District Court for a summary of the investigation.
The 35-year-old Polish man pleaded not guilty, while the suspected gunman asserted his right to silence.
De Vries was shot after making one of his regular appearances on a Dutch television show. He died of his injuries nine days later.
His killing sent shockwaves across the Netherlands and an outpouring of grief and condemnation.
Caretaker Prime Minister Mark Rutte called the shooting an „attack on a courageous journalist and also an attack on the free journalism that is so essential for our democracy, our constitutional state, our society“.
De Vries was the Netherlands’ most famous crime journalist and had recently had been an adviser and confidant for a witness in a major organised crime trial.