Those families used this kind of spell on their children. They would know exactly where the child went to to prevent the child from getting lost or getting into an accident.
When the child grew up, they would have a kind of life curse on their body. This curse was very powerful. If they were killed by someone, this life curse would be activated and immediately applied to the person who killed them. At the same time, the tracking curse that they had placed on them when they were young would also be activated and attached to the person. This way, their family could hunt down the person who killed them.
