San Diego logged 34 killings last year, a substantial fall from the 50 the year before. That decrease matched a fall in nearly every other major crime category in 2017 as well, from assaults and rapes to burglary and vehicle theft, the San Diego Union-Tribune reports. Decoding the sharp drop in homicides is tricky. Criminologists have identified a number of factors that appear to affect killings, like poverty, income inequality, unemployment and residential turnover. Gang activity, the drug trade and gun markets also fuel murders, experts say. A community’s relationship with the police and other law enforcement tactics play a role in preventing them. One researcher, after studying homicide trends in San Diego for decades, found the city’s large immigrant population may contribute to its low homicide totals, reasoning that they face job and housing pressures and don’t contribute often to crime.
“It’s really hard to say what causes a decline or an increase in murders,” San Diego police Capt. Brian Ahearn said. “Sure, there’s community-oriented policing and ShotSpotter and data-driven patrolling. But we had eight in January (2018) alone, and we were doing all those things.” Charis Kubrin, a professor of criminology at UC Irvine, said there’s never a single explanation for any trend in crime. “A lot of the action shaping homicide occurs at the neighborhood level — that’s where the real story is,” Kubrin said. San Diego police Lt. Manny Del Toro credited much of the decrease to healthy partnerships with an engaged community and aggressive police tactics designed to zero in on anyone involved in a killing — not just the murderer. “If there’s a violent crime in the area, we are flooding that area,” he said. “I mean, we are literally turning over stones. We’re stopping a lot of people. The heat is on.”