Certainly not all parents know for sure that their children did not run away, but could instead be the victims of foul play. Often parents are oblivious to the tensions, unhappiness or external pressures that lead a youngster to leave home. However, there are many situations in which parents are close enough to what is going on in their children's lives and have a good enough relationship with their children to know for sure that they did not run away. Often this firm belief on the part of the parents is buttressed by other factors: when the youngster disappeared, there was no evidence of planning. The youngster had not taken any clothes or treasured belongings or money. There were no major arguments, punishments, or troubles at school that could cause desperation. The youngster disappeared under circumstances that do not correspond with behaviors of a runaway. For example, the young person may have vanished on the way to the swimming pool or a movie or after getting into a strange car. The list of circumstances that argue against a kid being a runaway is lengthy.
Why is it then that police departments all over the globe persist in assuming that missing teenagers are runaways, unless evidence of foul play is documented? Yes, kids do run away. In fact, many kids run away, not just to avoid responsibility for something they have done, or because real or perceived environmental conditions at home or school are intolerable, or they think their parents don't care or don't love them, but sometimes they are running to something or someplace they believe is more exciting, more tolerant, more fun....
Yet, the history of serial murder is haunted by hundreds of cases of missing youngsters and adults, who the authorities have decided have chosen to runaway. Why? Some of the reasons are likely that the missing persons sections of police departments are frankly not staffed with the upwardly mobile officers and they are frequently understaffed and under-budgeted. Very few police departments are interested in expending limited resources when it is not crystal clear that a crime has been committed. Not unless, it is a high-profile case like the recent Chandra Levy case where there is a scandal involving a congressman and parents who were not about to let the police bury the case in a file cabinet.
In so many, many cases of serial murder the Atlanta child murders, the Moors murders in Britain, and the crimes of Ted Bundy, Jeff Dahmer and John Wayne Gacy to name a few well-known cases the list of victims is far longer than it would have been if the police had simply spent more effort separating out suspicious disappearances of young people from probable runaways.