The Chicago Police Department last year solved fewer than one in five murders committed during the year, the lowest rate for that crime in at least a half century, according to new police figures.
Of the 763 murders tallied by police in 2016, the department “cleared” just 151 — or 19.8 percent — down from a 2015 rate of 25.4 percent, according to the figures, obtained by WBEZ using the Illinois Freedom of Information Act.
“That is a very extraordinary figure,” said Thomas Alexander, a University of Maryland criminologist who studies clearance rates nationwide. “Less than 20 percent is a very, very low clearance rate.”
The drop coincides with a spike in gun violence and fraying police-community relations since the November 2015 release of a video showing a white police officer fatally shooting Laquan McDonald, a black teen. The violence has hit the city’s South and West sides especially hard.
The new clearance rate also continues a decades-long downward trend. As recently as 1991, according to CPD figures, the department was solving two-thirds of murders during the year they were committed.
Alexander, a police lieutenant in Hagerstown, Maryland, says cities with falling clearance rates tend to be experiencing an increase in violence between gang members.
“Gang-related homicides are very difficult to clear,” he said.
The department calculates its murder clearance rate two ways. The simple calculation accounts only for cases closed in the same calendar year in which the murder took place. That way generates the 19.8 percent figure.
The other calculation — the one that cities use for reports to the FBI — includes the clearance of murders committed in previous years. Chicago cleared 224 total cases in 2016. Dividing that figure by the number of murders committed during the year generates a 29.4 percent rate, an historic low.
That’s about half the nationwide homicide-clearance rate, according to Alexander.
“Cleared” does not necessarily mean brought to justice. In some cases, known as “exceptional” clearances, the suspect died or fled the country — or witnesses refused to testify. Chicago had 38 “exceptional” murder clearances in 2016, the lowest total in decades.
Many Chicago detectives say their job got harder in 2008, when the police department ordered them to quit holding suspects longer than 48 hours without bringing them before a judge. The change meant less time for questioning the detainees and checking into their alibis.
Another factor in the falling clearance rate over the years could be staffing cuts, experts say. In May 2008, the department employed 1,344 detectives, evidence technicians and police forensic investigators, according to city Human Resources Department data. The city allowed attrition to erode that number to 908 by November 2014. Over the next two years, it edged up to 958.
In September, Mayor Rahm Emanuel promised to add 200 detectives as part of a plan to expand the police department by 970 sworn officers by the end of 2018.
In a speech about the plan, police Supt. Eddie Johnson said the staffing increase could both curb crime and increase clearance rates, but he emphasized the difficulty of solving gang killings.
“You very rarely have a police officer that actually witnesses a murder or shooting,” Johnson said. “We need the public’s help in solving these crimes. So it’s not just a CPD clearance rate. It’s a Chicago clearance rate.”
Chicago’s low murder-clearance rate caught the attention of the U.S. Justice Department, which released a scathing report on the police department’s use of force this month.
“Identifying suspects in homicides is recognized as an important factor in preventing future homicides,” according to the report. “And there is broad consensus, including throughout Chicago, that increasing community trust and confidence in CPD is necessary for CPD to be able to clear more homicides.”
Chip Mitchell reports out of WBEZ’s West Side studio. Follow him at @ChipMitchell1. Michael Lansu is a digital editor for WBEZ. Follow him at @mikelansu.