The scholars, who are leaders in applying mathematics to interpret and make sense of police crime data, predict that the incidence should gradually decrease as people return to normal routines, but would likely increase again if there is a second wave of COVID-19 infections that prompts new stay-at-home orders.

Their study is published in the peer-reviewed Journal of Criminal Justice.

"Shelter-in-place rules, by mandating more time at home, are very likely to increase the volume of domestic or intimate partner violence, which thrives behind closed doors," said the study's senior author, Jeffrey Brantingham, a UCLA professor of anthropology. "During the COVID-19 pandemic, both Los Angeles and Indianapolis already have seen significant increases in domestic violence calls to the police, and we know domestic violence is one of the crimes least reported to the police."

The researchers analyzed police calls for service before and during the coronavirus pandemic -- from Jan. 2 to April 18 in Los Angeles, and from Jan. 2 to April 21 in Indianapolis. Los Angeles implemented "safer-at-home" rules were on March 20, and Indianapolis enacted similar orders on March 24. School, restaurant and bar closures were ordered in both cities on March 16.

The researchers also analyzed reported crime statistics -- different sets of figures reflecting that police investigations into alleged crime have occurred -- through April 10 in Los Angeles and April 18 in Indianapolis.

Both cities saw a statistically significant increase in domestic violence calls for service after stay-at-home policies, the researchers report. If stay-at-home rules are reinstated, the researchers expect the number of calls for service to remain high as long as these rules are in place.

By comparison, the numbers of reported robberies have decreased significantly in Los Angeles, and stayed relatively consistent in Indianapolis. Burglaries have decreased significantly in Los Angeles and slightly in Indianapolis. Vehicle thefts were moderately higher in Los Angeles, but unchanged in Indianapolis. Traffic stops were significantly down in both cities.

"Overall, these shifts are perhaps less substantial than might be expected given the scale of the disruption of social and economic life brought on by COVID-19," Brantingham said. "Overall, people were still finding opportunities to commit crimes at approximately the same level as before the crisis."

The researchers also write that physical distancing measures are likely to significantly alter and disrupt the conditions under which crime typically occurs. Crime patterns, they note, may provide valuable insights into whether individuals and communities are complying with critical public health measures.

Having crime patterns remain stable overall despite physical distancing measures may suggest the need to devote more resources to enforcing distancing rules, Brantingham said.

The study's co-authors include Andrea Bertozzi, UCLA professor of mathematics and director of applied mathematics; George Mohler, associate professor of computer and information science at Purdue University; Martin B. Short, associate professor of mathematics at Georgia Tech; and George Tita, professor of criminology, law and society, and urban planning and public policy at UC Irvine.

The research was supported by the National Science Foundation and the Simons Foundation.

Story Source:

Materials provided by University of California - Los Angeles. Original written by Stuart Wolpert. Note: Content may be edited for style and length.

Journal Reference:

1. George Mohler, Andrea L. Bertozzi, Jeremy Carter, Martin B. Short, Daniel Sledge, George E. Tita, Craig D. Uchida, P. Jeffrey Brantingham. Impact of social distancing during COVID-19 pandemic on crime in Los Angeles and Indianapolis. Journal of Criminal Justice, 2020; 68: 101692 DOI: 10.1016/j.jcrimjus.2020.101692