SPRINGFIELD – In the little more than two years that the Police Department has employed ShotSpotter acoustic technology to detect gunfire, the system has alerted police to more than 4,100 instances where a weapon has been fired.
Since its installation in July 2008, ShotSpotter has detected 4,158 gunshots, and contributed to 25 arrests and the seizure of 23 illegal firearms. In three instances it has alerted police to what would turn out to be homicides before the Police Department received a single 911 call.
All of this occurred in the roughly three of the city’s 32 square miles, the area covered by the ShotSpotter system.
“We’re getting spoiled by those three square miles,” said Sgt. John M. Delaney, aide to Police Commissioner William J. Fitchet. “Cops are getting used to it. It is something officers rely on.”
ShotSpotter, installed at a cost of $450,000, is designed to locate the scene of gunfire through a process called “acoustic triangulation.”
Since its installation in July 2008, ShotSpotter has detected 4,158 gunshots, and contributed to 25 arrests and the seizure of 23 illegal firearms. In three instances it has alerted police to what would turn out to be homicides before the Police Department received a single 911 call.
All of this occurred in the roughly three of the city’s 32 square miles, the area covered by the ShotSpotter system.
“We’re getting spoiled by those three square miles,” said Sgt. John M. Delaney, aide to Police Commissioner William J. Fitchet. “Cops are getting used to it. It is something officers rely on.”
ShotSpotter, installed at a cost of $450,000, is designed to locate the scene of gunfire through a process called “acoustic triangulation.”
As many as 62 sensors located around the city listen for any loud, sudden noise and then hone in on it. A computer takes the signal from the sensors and then combines it to get an exact position of where the shot was fired. The information is relayed to the police dispatcher and the mobile computers in each cruiser. The entire process takes 10 to 15 seconds.
“It gives us the audio and the exact location within 10 feet,” said officer Sean Sullivan of the Police Department’s radio repair division.
The advantage to all this is police can respond to the scene almost immediately, and know before they arrive if a gun has actually been fired and pretty much where it was fired, Delaney said.
“Now when we pull up on a scene, we have 100 percent knowledge if there was actually a shot,” he said. “It makes your approach different.”
Sullivan said there have been instances in which police were on the scene so fast after a shooting, they’ve witnessed the shooter trying to hide the gun.
In all, the system has triggered 39,962 times, but only around 10 percent of those were determined to be gunshots. The rest were the sound of fireworks, loud motorcycles, tractor trailers, backfiring automobiles, and, in one repeated case involving a South End parish, church bells.
The system also maintains a digital record of the sound that can provide police forensic information about the shooting, data that can be used as evidence in a criminal trial.
For example, Sullivan at his desk in the police station is able to call up the audio from a shooting in the area of Saratoga and Niagara streets in the Hollywood section of the city’s South End neighborhood.
ShotSpotter recorded six separate shots, each one at a slightly different location. The sensors determined the shooter was moving southwest at a speed of 18 mph.
“It’s a drive-by shooting,” Sullivan said.
Another audio clip was recorded at the time of the Aug. 6 shooting death of Timothy Knighton on Oak Street. In the span of 3 seconds, one can hear 10 to 12 shots. It’s the sound of someone shooting a semi-automatic weapon as fast as they can, he said.
One of ShotSpotter’s early successes was in the investigation of the shooting death of Alberto L. Rodriguez on Oct. 14, 2008, roughly two months after the system came on line, according to Delaney.
Rodriguez was found slumped over the steering wheel of his car on Ashley Street, dead of a gunshot wound. But ShotSpotter brought detectives to a spot several hundred yards away at Pine and Central streets, where they found spent shell casings.
Without ShotSpotter, police probably would not have found the shooting scene, Delaney said. Two men were arrested in connection with that shooting and await trial.
ShotSpotter significantly increases response times from police, Sullivan says. It allows officers to respond in seconds instead of minutes, he said.
It can be as much as five minutes after shots are fired before police receive a 911 call, he added. “Five minutes is a long time,” Sullivan said.
That is, if anyone ever calls.
Rodriguez was found slumped over the steering wheel of his car on Ashley Street, dead of a gunshot wound. But ShotSpotter brought detectives to a spot several hundred yards away at Pine and Central streets, where they found spent shell casings.
Without ShotSpotter, police probably would not have found the shooting scene, Delaney said. Two men were arrested in connection with that shooting and await trial.
ShotSpotter significantly increases response times from police, Sullivan says. It allows officers to respond in seconds instead of minutes, he said.
It can be as much as five minutes after shots are fired before police receive a 911 call, he added. “Five minutes is a long time,” Sullivan said.
That is, if anyone ever calls.
One of the things police have learned with ShotSpotter is how rarely people call 911 to report gunshots, he said.
Often when shots ring out, people in the vicinity scatter and look for a place to hide; they make sure everyone is OK, and then they think about calling the police, Sullivan said. Many times they don’t even call. “Typically, if someone calls 911 for shots fired, someone has gotten hit,” Sullivan said.
In some sections of the city, like the streets of Hollywood in the South End or Pine and Central streets in the Six Corners neighborhood, gunshots are relatively common and residents do not bother reporting every time they hear a shot.
Calling up a printout of all ShotSpotter activity at Pine and Central streets, for example, reveals a map literally covered with dots, each one signifying a confirmed case of gunfire. From September 2008 through this year, there have been 250 recorded incidents of gunfire in the area.
“To people, it’ s a part of life,” Sullivan said. “They only call 911 if someone gets hit.”
To calibrate the system, Sullivan said police sometimes have to go out and do test firings in which they’ll fire off a dozen shots into the air. No one has ever called 911 to report them.
The system covers roughly three square miles. Police do not like to reveal where the sensors are, but it is safe to say they are located in and around parts of the city where gunshots are most common, primarily Six Corners, the South End, areas of Forest Park and parts of the Old Hill, Upper Hill, McKnight and Bay neighborhoods. The cost of installation is about $200,000 per square mile, not counting maintenance.
Delaney said the department is hoping to secure grant money to cover the costs of expanding the system. “We’d kind of like to branch out to other areas,” he said.
The system covers roughly three square miles. Police do not like to reveal where the sensors are, but it is safe to say they are located in and around parts of the city where gunshots are most common, primarily Six Corners, the South End, areas of Forest Park and parts of the Old Hill, Upper Hill, McKnight and Bay neighborhoods. The cost of installation is about $200,000 per square mile, not counting maintenance.