Categorization of events in the criminal justice system happen very early in the process, often before the District Attorney’s Office charges a case. Initial classifications can change over time as the case evolves and more information becomes available. The data in this dashboard adhere to the original classification of a case rather that the classification of a case as it moves through the system. This has both strengths and limitations. The advantage in using this system is that if an incident is classified as, for example, drug sales, the arrest, charging, case outcomes, and future years of incarceration reports will all report on that case as a drug sale, even if the case is ultimately only charged as possession. By maintaining the original classification, a case can be “tracked” through the system, and in turn it becomes possible to know the outcomes for all cases that began in a particular category.
First, it is possible that the District Attorney’s Office charged the case differently than it was originally classified. As an example, an assault may initially be classified as “aggravated” because of the presence of a weapon. The District Attorney’s Office may not have found enough evidence that the weapon was used and may have only charged the case as a simple assault. The classification of aggravated assault, then, does not accurately reflect the incident as it moves through the courts, although it accurately reflects the assault at the time of the incident and arrest.
Second, the classification system that is used for offenses only allows for a single classification for each incident. This can lead to distortions when a person is ultimately charged with multiple cases from a single arrest. For example, if an individual shoots (non-fatally) three people in the course of a robbery, under this system all four offenses (the robbery and the three shootings) may be classified as “Robbery/Gun” even though three of the four cases that come from the incident would be for the shooting itself and not the robbery. This is because robbery with a gun is classified as “more serious” than an aggravated assault with a gun.
The District Attorney’s Office does not have data on crime incidents in the City other than what is available to the public through the City of Philadelphia’s open data program. We use OpenDataPhilly’s Parts I & II Crime Incidents dataset to study crime events, many of which do not lead to arrests. This leads to a number of limitations:
This database only records crimes classified as Part I or Part II crimes by the FBI, and does not include all violations. This means that not all crimes that happen within the City are shown in our Incident report.
The incidents recorded in this dataset are given a generalized of the FBI Uniform Crime Reporting (UCR) code. We cannot determine the specific nature offenses from the data available. For example, all Thefts are recorded as “Theft” in the Incident Report, while we can separate “Theft” from “Retail Theft” in all other reports. Another example of this is that all drug violations are recorded as simply Drug Offenses, and we cannot separate them into possession and sales as we do in all other reports.
This dataset is intended to allow members of the public, community groups, researchers, and other departments to access up-to-date and actionable data on crime incidents in Philadelphia. It is not intended to be an authoritative crime reporting database. The statistics generated from this database may not reflect the official reporting by the Philadelphia Police Department (PPD).
As a result of the point above, it is possible to derive three different numbers for Homicides from Police sources. We have summarized the OpenDataPhilly Incidents and derived the total number of incidents that have been classified in that data as Homicides. This is often different than the number reported on the front page of the Police Crime Maps & Stats page. Another number for homicides can be found in the Police’s weekly Crime Stats Reports; this number is also often different than those found in the Incident Data and Crime Maps & Stats page.
We have decided to include the Incident Report to help those who view the dashboard get as complete a view of the criminal justice system as possible, starting from the incident to the future years of supervision or incarceration generated.
The data by ZIP code available for download is actually by ZIP Code Tabulation Area, a geography defined by the United States Census Bureau using the majority ZIP Code for addresses in Census blocks. In densely populated cities like Philadelphia, ZCTAs and postal ZIP codes are functionally identical. For more information, visit the U.S. Census Bureau’s page on ZIP Code Tabulation Areas.
We use ZCTAs in the downloadable sets for two reasons: