AVA- Prosecutors have already said that a Turkish-born man previously identified as Gokmen Tanis has confessed to terrorist-related offences over the gun rampage.
"One of the seriously injured victims of the fatal shooting in the tram on 24 Oktoberplein in Utrecht died today of his injuries. He was a 74-year-old man," a prosecutors' statement said.
"This means that the 37-year-old suspect of the fatal shooting on March 18 is now suspected of four-fold murder or manslaughter with a terrorist objective, attempted murder and a threat with a terrorist objective."
Another seriously injured victim remains in hospital while a third injured person has returned home, prosecutors added.
The investigation continues and a court will decide at the end of next week on the alleged gunman's further detention, the statement said.
Prosecutors said on Friday that Tanis had confessed to terrorist charges over the rampage, and said he acted alone. Several other people were arrested but released.
Dutch authorities previously said they were probing whether Tanis "acted out of a single terrorist motive or whether from personal problems in combination with radicalized ideas."
Thousands of Dutch mourners including Dutch Prime Minister Mark Rutte took to Utrecht's streets on Friday evening to pay their last respects to the victims of the rampage.
Rutte tweeted on Thursday about the "immensely sad news that one of the victims of the attack in Utrecht died."
"We all feel the same as last week: disbelief, impotence and also anger. Our hearts go out to the relatives. I wish them much strength," Rutte said.
If the suspect is eventually convicted of terrorism offences it will be the worst terror attack in the Netherlands, which has until now been spared the kind of large-scale attacks that have rocked its European neighbors.
However there have been a series of recent scares. In August, a 19-year-old Afghan with a German residency permit stabbed and injured two American tourists at Amsterdam's Central Station before being shot and wounded.
In September, Dutch investigators said they had arrested seven people and foiled a "major attack" on civilians at a major event in the Netherlands.