As Philadelphia police concentrate on lowering the city's homicide rate, a new study has found evidence of a predictable pattern for one type of shooting — those classified as “near-repeats.”

“Our study found that once there is a shooting on a street corner, the risk of another shooting within a block of that location over the next two weeks increases by a third,” said Criminal Justice Professor Jerry Ratcliffe, who coauthored the study with his colleague in the Criminal Justice Department, Professor George Rengert.

The findings, published last month in the Security Journal, build on previous research at Temple that showed that slightly more than half of the people who are shot in Philadelphia are shot within 800 feet — about two blocks — of their homes.

“Together, the two studies point to the reflexive, retaliatory and neighborhood nature of much of our city’s violence,” Ratcliffe said.

“Our research supports anecdotal evidence from police and community members who say that the shootings in the city are not all related to drugs or organized crime. The pattern of near-repeat shootings suggests that the second shootings are often a response to the first—either an act of retaliation or the result of intensified levels of fear and agitation,” he added.

In the latest study, using data supplied by the Philadelphia Police Department, the near-repeat phenomenon was found to occur throughout the city, regardless of the neighborhood.

If the risk in a particular neighborhood was already low, the increased risk remained low. However, if a neighborhood’s risk started out high, then the increased risk after one shooting became significant, Ratcliffe explained.

According to Ratcliffe, while many people believe violence will solve a conflict, the evidence clearly demonstrates that the opposite is true: One shooting only serves to escalate the level of violence in a community.

A former police officer with the Metropolitan Police in London where he served on patrol duties in an intelligence and information unit, and as a member of the Diplomatic Protection Group, Ratcliffe has focused much of his research on the use of strategic thinking and intelligence-led policing to guide police work.

“Now that we know when and where the threat of a shooting is at its highest, we can better direct crime prevention activities, such as stop-and-frisk or community-watch surveillance, to specific areas for specific time periods.

“There are no easy answers, but using data to inform police tactics can allow us to target resources and take a proactive approach when responding to street-corner violence,” said Ratcliffe.