I wrote "young criminals" I should be more clear, the gangs often use people below the age of 18 to commit murders since you then you get 4 years juvenil but are usually out before that due to 2/3 rule. There is even a saying in these circles: "Att brösta en 4:a för att bli en 100-gubbe" meaning Do the 4 years and become a 100-man, in other words commit a murder and you get respect and will be taken care of when you get out.