MADISON, Wis. - The Wisconsin Supreme Court on Thursday upheld the conviction of a Milwaukee man who was arrested by officers responding to a report from gunshot location technology, ruling that the officers had reasonable suspicion to stop him beyond just the gunshot technology.
The court ruled unanimously against Avan Rondell Nimmer, who was taken into police custody in 2019 after officers observed him walking about 100 feet from the site of a ShotSpotter report near his home in Milwaukee.
Nimmer argued that officers had no reason to stop him, contending that ShotSpotter detects gunshots but doesn't identify shooters and he was just out looking for his girlfriend.
A state appeals court agreed with him, but the Supreme Court reversed that ruling. Justice Rebecca Bradley wrote for the majority that officers had reasonable suspicion to detain Nimmer in part because ShotSpotter is reliable, he was in the area minutes after the technology detected gunfire and he appeared to be hiding a weapon.
Nimmer’s appellate attorney, Mark Rosen, disagreed with the decision.
"I think they got it wrong, so I’m just going to leave it at that," he said.
The use of ShotSpotter technology in policing has been attacked by some as problematic and potentially misleading. ShotSpotter, a network of surveillance microphones used to detect gunshots, is powered by an algorithm guarded by its creators as a trade secret. An AP investigation earlier this year identified serious flaws in using ShotSpotter as evidentiary support for prosecutors.
AP’s investigation found the system can miss live gunfire right under its microphones, or misclassify the sounds of fireworks or cars backfiring as gunshots. Forensic reports prepared by ShotSpotter’s employees have been used in court to improperly claim that a defendant shot at police, or provide questionable counts of the number of shots allegedly fired by defendants. Judges in a number of cases have thrown out the evidence.
ShotSpotter says its technology is accurate and has been successfully admitted in more than 200 court cases nationwide.
When Milwaukee officers responded to the alert outside Nimmer's residence in June 2019, Nimmer was the only person in sight less than a minute after four gunshots were reported, according to court records.
Officers approached Nimmer after noticing that he was walking quickly away from their squad car. In response to their approach, Nimmer reached for his left side and turned his body away from the officers.
One of the arresting officers testified that he believed Nimmer's behavior suggested he was hiding a weapon.
Upon stopping and searching Nimmer, he revealed to officers that he had a handgun tucked in his waistband, saying, "The gun's on my waistline, bro." Because of a previous felony conviction for possession of THC with intent to deliver, Nimmer was prohibited from possessing a gun.
Nimmer said in court that he was in the street to look for his girlfriend, who had left his house moments before he heard gunshots outside.
His trial attorney sought to suppress the handgun evidence, arguing officers had neither reasonable suspicion nor probable cause to stop and search Nimmer. The motion was denied, and Nimmer was sentenced to two years in prison and two years extended supervision for possession of a firearm by a felon.
The trial court ruled that timing was the key to officers' reasonable suspicion, stating that "anyone they encountered within a minute or two of receiving the alert should have been investigated if they were within in a couple of blocks of the alleged shots fired."
The Wisconsin Court of Appeals reversed the trial court’s decision, citing multiple cases as precedent for their opinion that Nimmer’s presence in an area where criminal activity wasn't enough to detain him. The appeals court also ruled that Nimmer's behavior on the scene was insufficient for reasonable suspicion.
Justice Rebecca Dallet, joined by two other justices, wrote a concurrence that agreed police had reasonable suspicion to stop Nimmer but argued that the majority opinion relied too heavily on the ShotSpotter alert.
"No matter how accurate ShotSpotter is or how quickly officers respond to a ShotSpotter alert, it cannot be used as a dragnet to justify warrantless searches of everyone the police find near a recently reported gunshot," Dallet wrote.