Dutch prosecutors said Thursday they will charge the suspect in this week's deadly tram shooting in the city of Utrecht with multiple murder charges with terrorist intent.
Prosecutors believe Turkish-born Gokmen Tanis acted alone Monday when he allegedly killed three people and seriously wounded three others.
Prosecutors and police said in a statement they are still investigating whether the 37-year-old suspect "acted out of a single terrorist motive or whether from personal problems in combination with radicalized ideas."
The suspect was arrested after an eight-hour search that virtually closed the city. Police later arrested a fourth suspect and are trying to determine "whether this suspect played a supporting role in the shooting."
Tanis is scheduled to attend a closed-door court hearing on Friday. Prosecutors also said Tanis will undergo a psychological examination.