Police test ShotSpotter in the Mission
By: John Upton
December 19, 2008
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| Hush-hush: Police are keeping the Mission district locations of ShotSpotter a secret from the public. (Bret Putnam/Special to The Examiner) |
SAN FRANCISCO — The all-too-familiar sound of gunfire that erupted in the Mission district Thursday night rang in the launch of the newest crime-fighting tool for the violence-plagued neighborhood.
The shots were fired from handguns by police officers — at a stack of bulletproof vests — to test, calibrate and fine-tune roughly 20 sound sensors that will allow police to monitor gunfire in a square mile of the Mission. The area is part of Mission Police Station’s jurisdiction, which has accounted for 45 homicides since 2006.
Residents were warned just prior to the tests through megaphone-blasted alerts from squad cars and by street closures.
At 9:28 p.m., the first test proved successful when Officer Charles Bonicci fired and the system picked it up, according to police Lt. Mikail Ali.
Police won’t tell the public which parts of the Mission will be monitored, but the locations of Thursday’s four tests offer some clues: the first one at 18th and Lexington streets; 22nd and Bartlett streets at 9:47 p.m.; 23rd Street and Treat Avenue at 10:02 p.m.; and 18th and Bryant streets at 10:20 p.m.
The final test at 18th and Bryant was the only one to prove unsuccessful, but police still officially started using the ShotSpotter system afterward to monitor the neighborhood for the telltale acoustic signature of gunfire, Ali said. An additional sensor will be added in that area to solve the problem, he said.
The $200,000 system, purchased with state grants, could help police solve crimes, but it won’t be as helpful at preventing crimes, according to Mission station Capt. Stephen Tacchini. The City is nearing 100 homicides this year, after a decade high of 98 in 2007.
“It’s a detection system,” Tacchini said. “It’s not a preventative measure by any means.”
ShotSpotter, which was invented by a group of Stanford research scientists in the 1990s, is also being used by 32 other cities, according to company spokesman Gregg Rowland.
It is also currently in use in the Western Addition neighborhood and Bayview District.
ShotSpotter uses pizza-size audio sensors and trigonometry-based calculations using the speed of sound to alert police to the precise location of a shooting or explosion, according to Rowland.
Between March and September, a ShotSpotter system that monitors 1.3 square miles of Bayview alerted police to 166 instances of gunfire, helping lead to the June arrest on Cashmere Street of an Antioch man who fired a stolen pistol, according to Ali.
It also helped police find evidence they might not have found for the investigation of a March 9 homicide, because the slain victim died hundreds of feet from where he was shot, according to Ali. Since the crime has not been solved, he would not say what evidence was found.
ShotSpotter might be added to other neighborhoods if funding grants can be secured, according to Ali.
Where the wild shots are
ShotSpotter is currently being used in the Bayview district and Western Addition neighborhood. It was launched in the Mission district Thursday night.
Bayview district figures for March 7 through Sept. 20:
1.3 Square miles monitored
166 Instances of gunfire detected by ShotSpotter
21 Instances of gunfire reported to police by citizens
1 Homicide detected by ShotSpotter
1 Attempted homicide detected by ShotSpotter
1 Arrest due to ShotSpotter
Western Addition figures for April 11 through Oct. 21:
1 Square mile monitored
89 Instances of gunfire detected by ShotSpotter
34 Instances of gunfire reported to police by citizens
2 Homicides detected by ShotSpotter
1 Attempted homicide detected by ShotSpotter
1 Arrest due to ShotSpotter
Source: Mayor’s Office of Criminal Justice
