In Today’s Maths Class, We Will Learn To Catch A Serial Killer!!

From about 1985 to 1995, for an entire decade, a serial rapist haunted the town of Lafayette, Louisiana. The man broke into houses and raped his victims at gunpoint.

Dr. Rossmo, a well known Geographic profiling expert was called in for help. At first the cops were skeptical about how effective his methods would be in catching a criminal who had hoodwinked the local police force for a decade.

“Look at it this way”. Dr. Rossmo explained his concept. “Imagine a sprinkler watering a garden. Now, even if you know where a sprinkler is, you can’t possibly predict where the next drop of water will fall. However if you have knowledge of sufficiently large number of locations where the water drops fell, you can find where is the most probable location of the sprinkler.”

“So if you are trying to analyze the data available so far and trying to predict where the next crime will happen, it is not going to work. But we know the locations where crime happened, so let’s try to guess the location of the source, the criminal.”

Dr. Rossmo put forward a theory that a criminal who commits a series of crimes does so in a particular pattern. The criminal does not want cops in the vicinity of his residence. So he will choose locations sufficiently far from where he stays. However the criminal also wants to have good knowledge of the crime location for planning the crime well. So the location will not be too far from the residence of the criminal.

Consider the diagram above. Around the serial criminal’s most frequent geographic location, which is normally residence or workplace, there lies a “buffer zone”, a zone within which the criminal does not want trouble. Outside of this buffer zone likes “hot zone”, or “zone of comfort for committing crimes”. Outside this “hot zone” is all “silent zone”, zone which criminal considers too far to do anything. Identifying these zones gives a good sense of the location of the criminal. Using the sprinkler analogy, if the crime locations are the places where water droplets fall, then the location of sprinkler is the location of the criminal.

Based on the data and forensic information, Dr. Rossmo created a mathematical formula to model criminal behavior. Based on this formula, he predicted a small area as hot zone, which was not previously considered as probable area for searching the criminal.

The cops carried out extensive search for a while, which yielded nothing. Finally one day, based on an anonymous tip, cops investigated one of their own, a Sargent, who had recently changed residence, but used to reside in the ‘hot zone’ before. His DNA matched the DNA at crime scenes. The rapist was jailed and the decade long case was finally closed.

This case and the area of criminal investigation overall is the classic example of how the latest information age has capability to transform life and society, how the information is the strategic asset of todays world and how if you are willing and creative, you can push the limits of possibilities beyond imagination.

In our schools in India, we learned one after another mathematical skill, without ever bothering to ask “why learn this”. All I remember thinking that time was how to get best grades in school, so that I can get the best job or admission to the best school for further studies, which will guarantee a happy and secure life.

Perhaps it’s time to ask ourselves some questions.

While India produces 10 times more software engineers and science graduates than Canada, and Indian police force is severely limited in resources compared to Canada, making it a perfect place to apply IT based criminal solutions, when will India have it’s own Dr. Rossmo?

When will our education system break the shackles of centuries old legacy of all-theory-no-application?

When will an enthusiastic teacher in a school in India will enter the mathematics class and declare “In today’s class, we will learn how to catch a serial killer.”