The boy has been taken into care by social services, the Swedish Prosecution Authority writes in a press release.
The two women were arrested on Thursday. They are in their twenties and are suspected on probable cause of being an accessory to murder and three counts of attempted accessory to murder.
"I assess that the suspicions against the two women are so strong that I will likely request their detention later today," says senior prosecutor Caroline Carlquist, who is leading the preliminary investigation, in a comment.
The victim, a man in his 20s, was shot in a car at around 11pm on Friday. He was taken to hospital and pronounced dead. Several people were in the car when it was shot.
