CHICAGO — A growing shortage of Chicago Police officers is impacting how the department staffs a key office that helps track people convicted of certain crimes.

WGN Investigates has previously reported on the closures and delays at the Criminal Registration Unit on the city’s South Side.

WGN Investigates found people waiting in line for hours, simply to comply with a state law that requires arsonists and those convicted of sex and gun crimes to check-in and register with police. There is no other registration unit in the city.

Kenneth Baker shared his story with WGN Investigates about how he couldn’t register because the unit was closed due to staffing shortages.

Baker, 48, is no saint. His rap sheet includes convictions for sex offenses. But on a recent weekday, he did show up to register at the facility at 93^rd and Cottage Grove Avenue but could not because the office was closed.

He wasn’t alone. WGN Investigates spoke with others who were unable to follow the law because Chicago Police had no one to staff the unit.

Patricia Casey is a retired police commander who used to lead the unit.

“Right now, CPD is not doing their part to let the registrants follow the law,” Casey said. “They are short-staffed right now. They are down approximately half the number of persons they had several years ago, and registrations are growing.”

Chicago Police were unable to provide data on how many people have been turned away. But the department did acknowledge its dealing with staffing issues.

In 2018, Chicago Police counted 13,242 sworn department members. It now has more than 11,600, or about 1,600 less than it did just four years ago.

The decline is having an impact on the criminal justice system. In Baker’s case, possibly leading to an unnecessary arrest.

Days after WGN interviewed him, Baker was arrested for failing to register as a sex offender, the very thing he was trying to do but couldn’t because the office was closed.

“It’s so unjust,” said Adele Nicholas, with nonprofit Illinois Voices for Reform. “People are often making choices between keeping their jobs or waiting in line all day to fill out this piece of paper. I’m sure that Mr. Baker is not alone.”