In March, The New York Times published "Rampage Killers," a four-part series that revealed the results of a database project we undertook of 100 cases of explosive public murder over the past 50 years. These killings are not new, we said, although they may have increased in the 90s. We found more evidence of serious mental illness than of fascination with violent video games, and pointed out some important ways these criminals differed from regular murderers.

The series showed what you can do with the techniques of precision journalism. It showed how you can speak with authority when you let computer tools help you manage and distill large amounts of information.

The seeds were sowed at The New York Times in 1999, when Thom Shanker, an editor in the Washington bureau, suggested a few days after the Kosovo pogrom