While mucking through the city’s “Part I” crime data this morning, AxisPhilly made an interesting discovery: since just Friday, the data has been amended to include three, not one, categories of “homicide” — and now makes a distinction between “murder” and other instances of “homicide” in the city.

City Chief Data Officer Mark Headd, initially as surprised by the find as we were, quickly confirmed that the Philadelphia Police Department had broken down the category of “homicide” into three sub-categories:

-       Homicide – Criminal

-       Homicide – Justified

-       Homicide – Gross Negligence

The move follows some confusion last week when we reported that the figures for “homicide” listed in the police data were significantly higher than the year-by-year counts offered in police reports, variously referred to as “murders” and “homicides” by public officials.

The count most of us see and hear, it turns out, is the number of “murders,” — or criminal acts of homicide — and not the total instances of “homicide,” a broader category which boils down to one person killing another person.

(The FBI requires that cities report only statistics for “murder and non-negligent manslaughter”).

The police data now reflects the distinction. It also shows that the total number of killings, justified, accidental, or criminal is significantly higher — about 20% to 25% higher in the past five years — than the number of murders we tend to hear in the news and in the mayor’s annual public safety evaluations.