March 28 (UPI) — A fourth victim injured in a shooting aboard a tram in Utrecht, Netherlands, last week died Thursday, the Dutch Public Prosecutor’s Office said.

Officials said the 74-year-old man from De Meern died from his injuries, though declined to reveal the cause of death.

The man was injured March 18 when a gunman opened fire on a tram at the 24 October Square station before leading police on an hours-long manhunt across the city. Turkish national Gokmen Tanis, 37, confessed to the shooting and said he acted alone.

Police said they found a letter in a getaway car he used that makes them believe the shooting was a terror attack.

Prosecutors said Tanis now faces four counts of murder with terroristic objective.

In addition to the 74-year-old man, the dead include a 19-year-old woman, a 28-year-old man and a 49-year-old man. Prosecutors said one of the two seriously injured victims was in the hospital as of Thursday.

Investigators said it doesn’t appear the gunman knew any of the victims.