The city office focused on surveillance technology and public data ethics, Smart City PDX, isn't certain that a technology used to monitor gunshots is the right tool to address Portland's gun violence problem. In a report prepared for City Council, staff with Smart City PDX explain that the technology—called ShotSpotter—could open the city up to legal risks, financial woes, and weaken Portlanders' civil rights in the process.
"The city needs to rely on technology trusted by the community and city staff," reads the report, published August 4.
ShotSpotter uses a number of small microphones placed on street lights, telephone poles, or other tall structures in city neighborhoods to detect sounds that are akin to a gunshot. When that sound is registered by a microphone, ShotSpotter sends local law enforcement the general location of the sound for a quick response. The ShotSpotter company advertises its product as an alternative to police departments relying solely on 911 calls to be alerted to a shooting.
More than one hundred cities currently employ the technology. In July, a volunteer-led city commission issued a recommendation to Portland City Council to adopt the technology. Smart City PDX was instructed to review the recommendation before council considered the idea. In their report, city staff identified a number of potential problems the technology could present if introduced in Portland.
One of the leading concerns among police accountability groups that oppose ShotSpotter is that it can falsely characterize a loud sound as a gunshot. That can mean a slammed car door or backfiring truck could, within minutes, bring a swarm of police to a neighborhood searching for a shooter.
According to the ShotSpotter company, the technology has a 97 percent accuracy rate and a false positive rate of 0.5 percent. Measuring that against Portland's shooting trends, the city estimates that ShotSpotter would deliver 66 false positive reports each year.
Smart City PDX staff believe that this combination could be dangerous to members of the public who may be mistaken for a shooter during a false alarm.
"Given that this technology preempts law enforcement units expecting lethal weapons present in the incident," the report reads, "the risk of having an unintended lethal encounter in those false positive detection[s] can still be too high of a risk for the city."
This presumption of a shooting could also "be used to justify stop-and-frisk actions on residents," the report reads. It's a valid concern.
A 2021 study by Chicago's Office of the Inspector General found that ShotSpotter accurately detected a gun-related criminal offense just 9 percent of the time officers were drawn to a scene by the technology. The office also found that an alert from ShotSpotter—regardless of whether or not it was tied to an actual gunshot—became officers' rationale for stopping and questioning people in a neighborhood or patting them down for weapons.
The Focused Intervention Team Community Oversight Group (or FIT COG), which penned the ShotSpotter recommendation to City Council mentioned this report and concern in their July proposal—but did not fully examine its consequences. Smart City PDX writes that enabling a technology that increases baseless encounters with police could "[erode] public trust in Portland Police and [impact] civil liberties and civil rights."
This concern is magnified by the fact that the FIT COG suggested ShotSpotter be deployed in neighborhoods that see the most gun activity, which are disproportionately home to Portlanders of color—a population already disproportionately stopped by police.
"Given that the highest number of gunshot incidents in the city are present in Portland neighborhoods where more Black and Latino families live," the report reads, "it is unavoidable that this technology will impact these communities and that inequitable impact needs to be regularly assessed."
The Smart City PDX analysis also pointed to ShotSpotter's tenuous record in court. The report notes that Chicago is currently being sued for allegedly misusing ShotSpotter data, resulting in the death of a 65-year-old man. ShotSpotter itself is currently being held in contempt of court in Chicago for refusing to turn over documents on how it assesses the data it collects.
"This action raises concerns regarding the level of transparency required in this high risk-high impact surveillance technology," the Smart City PDX report reads.
The report did not characterize ShotSpotter as a threat to personal information for its ability to record audio, as the company has pledged not to share raw audio with law enforcement.
Lastly, Smart City PDX pointed to the data and analysis either missing in FIT COG's recommendation—or thought to be incredibly vague. Specifically, the report notes that FIT COG did not mention the price of ShotSpotter, which can reach up to $90,000 per square mile annually.
"The business model of ShotSpotter may push the cost of the technology considerably high in order to reach the required effectiveness," the report reads. "The costs are linked to square miles of coverage and potentially not include additional costs for installation, training, data analysis, communications, and community outreach."
In conclusion, city staff write that, "The level of accuracy of the technology might not be enough due to the high risk and high impact and the involvement of lethal force in responding to sensor detection." The report urges city leaders to conduct a more in-depth analysis of the technology to better understand the risks.
Members of FIT COG, which focuses on overseeing Portland police who respond to gun violence, don't see ShotSpotter as a panacea to the city's gun violence issues. In their recommendations to council, FIT COG noted that the technology could be one of several tools to address shootings, and urged the city to consider it "as part of the overarching gun violence response strategy."
City Council has yet to set a date to hear FIT COG's ShotSpotter recommendation, which will be accompanied by Smart City PDX's analysis.