It appears Chicago decided to go the British route on crime numbers:

change them around and lie so the mayor and CoP look better.

And if a bunch of murder victims wind up being ignored?  Well, that's the price they pay for Mayor Rahm and Chief McCarthy.
Given the finding of homicide—and the corroborating evidence at the crime scene—the Chicago Police Department should have counted Groves’s death as a murder. And it did. Until December 18. On that day, the police report indicates, a lieutenant overseeing the Groves case reclassified the homicide investigation as a noncriminal death investigation. In his writeup, he cited the medical examiner’s “inability to determine a cause of death.”

That lieutenant was Denis Walsh—the same cop who had played a crucial role in the alleged cover-up in the 2004 killing of David Koschman, the 21-year-old who died after being punched by a nephew of former mayor Richard M. Daley. Walsh allegedly took the Koschman file home. For years, police officials said that it was lost. After the Sun-Times reported it missing, the file mysteriously reappeared.

But back to Tiara Groves. With the stroke of a computer key, she was airbrushed out of Chicago’s homicide statistics.