England/Wales
Within England/Wales, criminal responsibility is considered the age of 10 years. This is when a child becomes criminally responsible for their actions and the consequences of their actions. From this age onwards, they can be prosecuted for any criminal offence in a Youth Court. In exceptional circumstances, most notably the case of the murder of James Bulger in Liverpool in 1993, children can be tried as an adult in an adult court.
From the age of 17 onwards, individuals are then considered an adult in the eyes of the law. Therefore, all punishment given by the courts or other law enforcement agencies will rest solely upon them.
^^^^ from Wiki