LONDON — The main suspect in a deadly shooting on a tram in the Dutch city of Utrecht had no direct relationship with the victims, police said on Tuesday.

Three people were killed and several others injured in the attack on Monday. Police identified the main suspect as Gökmen Tanis, a 37-year-old born in Turkey, based on surveillance footage.

Police released this image of Gökmen Tanis Police Utrecht / AP

Despite there being no connection between the victims and the alleged shooter, police say the motive of the attack is still open and could be terrorism or a family matter.

Tanis had fled the scene by car but was detained by police later in the day. On Tuesday, police provided more detail in a series of tweets saying the suspect had been arrested at a house northwest of the city center and also had a gun.

Two other men, 23 and 27, were also detained. Police say their relationship to the shooter is still unknown.

More details were also released about the victims.

A 19-year-old woman from the nearby city of Vianen was killed along with two men from Utrecht.

Those suffering serious injuries include a 20-year-old woman from Utrecht, and a 74-year-old man and 21-year-old woman from neighboring cities.