I’d like to welcome my first guest poster here atMath for Grownups, Carole Moore.  Carole is a fellow writer and the author ofThe Last Place You’d Look: True Stores of Missing Persons and the People Who Look for Them, which hit bookstores in May.  Her book is a gripping account of a variety of missing persons cases around the country.  A former police detective, Carole knows her stuff.

She also knows how darned scary missing-persons statistics can be.  And so she’s offered to take a closer look at these numbers and what story they really tell.  This is a critical way that we can use math without even being aware.  See, as scared of math as many of us are, we may also be inclined to trust numbers.  Unfortunately, without some perspective and context, numbers don’t mean a thing.  Keep reading…

When it comes to crime, statistics can be misleading. The truth is in how you break down the numbers. Let’s look at one example:  According to the U.S. Department of Justice, 797,500 children under the age of 18 were reported missing in one year’s time. That’s an average of 2,185 kids per day. What’s more interesting is what those numbers don’t say:

First, the category of the report from which they’re drawn (NISMART-2) specifies “reported” missing. That means that some kids who disappeared in the same time bracket were not reported within the reporting period. It doesn’t necessarily mean they weren’t reported at all – although many aren’t. Illegal immigrants often won’t call police out of fear of reprisals, and the children of the mentally ill, transients, the homeless, prostitutes and drug users, as well as foster kids, often escape the count. So, while the figure 797,500 sounds huge, the actual number of missing children in a year well exceeds “reported” missing.

Now, look a little closer at those numbers, starting with family abductions, which account for 203,900 children reported missing, and 58,200 kids classified as non-family abductions. That leaves 535,400 children unaccounted for – of these children only 115 were considered “stereotypical” kidnappings. (Examples of stereotypical kidnappings are usually extreme and include cases such as those of Jamie Duggard and Adam Walsh.) The remaining 535,285 children fit in none of these specific categories.

The children left are grouped miscellaneously. For example, a child reported missing after stopping at a friend’s house following school (and who didn’t notify a parent or caretaker) would now be a reported missing child for statistical purposes. So would a child who becomes lost or hides out whose disappearance is reported – even if the child is really not missing in the truest sense of the word, they would be classified as “reported missing.”

My point is that while the statistics here don’t lie, they also don’t tell the whole story in and of themselves.  Many missing children are never reported missing, while many of the reported missing really aren’t missing at all. To truly understand crime stats, it’s important to dig deeper than the numbers.

Carole Moore is a former police detective and current freelance writer, as well as contributing editor and columnist at Law Enforcement Technology.  You can learn more about her atwww.carolemoore.com.

Do you have questions about crime statistics?  Ask them in the comments section!