July 27, 2015

  • Mass killings happen about every two weeks

    Statistics on gun deaths are hard to find, often because local jurisdictions report them unreliably, and often because the gun enthusiasts are opposed to anything resembling a national database.

    In 2012, USA Today began a multi-month-long investigation into data to discern other deadly patterns, culminating in the publication of “Behind the Bloodshed” in 2013.  It is believed to be the most reliable journalistic resource to date on mass killings in the U.S. -- that is, killings of at least four victims -- and the team updates it regularly.  [ Interview ]

    mass-killings-jodi-upton-249x300
    Project manager Jodi Upton, senior database editor at USA Today, led a team of data experts, designers, editors, web developers and others to create an interactive presentation of these results.

    It turns out there is no "magic bullet" solution.  Most mass killings are committed:

    • with handguns, and not with rifles or automatic weapons.
    • with legally owned weapons.
    • against family members.
    • by a killer their victims knew.
    • by males.
    • in streaks.

    Statistically, mass killings can have a "contagion" effect lasting, on average, about 13 days.  That can happen even when the killer is not directly aware of other incidents, as is often the case for the hundreds of mass killings that do not generate days of national coverage, says Sherry Towers, professor of statistics at Arizona State University’s Simon A. Levin Mathematical, Computational and Modeling Sciences Center.  [ Sherry Towers ]