Johns Hopkins University is installing sensors this week that could help police pinpoint the source of gunfire. It's part of a pilot program from SECURES Gunshot Detection System, based in Reston, Va., and donated by the company to help attract publicity.

SECURES is one of at least five companies that are dabbling with this new technology that uses strategically placed microphones to pick up the sound of gunshots and then locate the source to within 10 feet. Detectors have been installed throughout the Charles Village and Homewood communities.

More than 30 cities around the country, including Washington, are using this technology. Scanning various Internet sites, I've found some interesting conclusions. Many departments, such as Minneapolis, have discovered that many gunshots do not get reported to 911. As a result, they ended up with a spike in gunshot-related statistics when ShotSpotter was installed. But over time, the department reported a drop in shootings, in part due to the quicker police response time.

The Minneapolis Police Department publishes a weekly map showing all the locations picked up by the sensors. I've harped on this countless times here and in my column -- that providing such information to the public is vital to keeping people informed. I recently wrote about a case in which a car was shot up, but residents standing at the crime scene were told the next day by police that nothing had happened because no report was written. Take notice Baltimore -- your colleagues in Minneapolis provide MAPS TO THE PUBLIC of every gunshot picked up by the computers.

In Washington, police reported that their ShotSpotter network, deployed in one of the most violent districts, has already helped solve several homicides, and enabled officers to respond to one quickly enough to catch the shooters in the act, according to the Washington Post.

The National Institute of Justice studied this technology and here are its key findings:

Gunshot detection systems are likely to reveal rather high citizen under-reporting rates of random gunfire problems (23 percent of incidents are reported). The technology is likely to increase the workloads of police officers, particularly if departments dispatch a patrol unit to every gunfire incident detected by a technological system.

Gunshot detection systems are not likely to lead to more arrests of people firing weapons in urban settings because it is highly unlikely that offenders will stay at a gunshot location long enough for the police to arrive.

Gunshot detection systems seem to offer the most potential as a problem-solving tool and would fit nicely within the emerging problem-oriented policing paradigm. The technology can help police identify random gunfire hot spots and develop strategies to address the problem. 

The SpotShotter web site is filled with links to news articles about its product. In Baltimore, city authorities say the technology is not quite proven yet to consider for broader deployment. It's not cheap. It costs $2 million install in just one police district in Washington.

The SECURES system could be a good test, though I wonder about its placement. Yes, Hopkins is getting it for free, and I suppose they'd get criticized for not using the gift for the benefit of their students. But Charles Village and Homewood are far from the most dangerous neighborhoods in the city; only two people were shot and there were 22 reports of gunfire in the coverage area this year, according to Baltimore Sun police reporter Justin Fenton. Maybe Hopkins could have deployed in East Baltimore, where its hospital is building a new biotech park and wiping out acres of old rowhouses in what is still a violent neighbhorhood.