A Chicago police sergeant today pleaded guilty during a disciplinary hearing to bringing discredit to the department for actions that led to a woman killing herself with his gun in 2009 while he was at her apartment while off-duty.

A Chicago police sergeant pleaded guilty during a disciplinary hearing Friday to inattention to duty and bringing discredit to the department for actions that led a woman to kill herself with his gun in 2009 while he was at her apartment while off-duty.

Sgt. Steven Lesner admitted he left his gun unattended and bought Catherine Weiland alcohol while on duty. He testified she fatally shot herself while he was in the bathroom at her apartment. The two had met earlier that night when Lesner responded to a call of a disturbance between Weiland and her boyfriend at a Northwest Side restaurant.

“I feel terrible that a human life has ended,” Lesner testified at a Chicago Police Board hearing that took up much of the day. “I feel sorry for what I've caused the Weiland family.”

In January the board rejected Superintendent Garry McCarthy's recommendation that Lesner be suspended for 60 days as inadequate and called for the hearing.

According to police reports, Lesner bought Weiland a bottle of wine when he was still on duty and drove her home. She later invited him to her apartment when his shift ended, and he returned there with even more booze.

Weiland, whom a relative had said was bipolar and had attempted suicide previously, shot herself in the right temple with her right hand, according to the reports. Yet it was her left hand that tested positive for gunshot residue.

In testimony Friday, Detective Thomas Conley, the lead investigator on the case, theorized that the test results might have been mixed up or that Weiland shot herself while holding the gun with both hands. Acting out how Weiland might have used both hands, Conley twisted into an awkward position, raising both arms and clasping his hands by the side of his face.

“I don’t think she realized how much pressure it takes to shoot a gun,” Conley said.

Lesner’s lawyer, Thomas Pleines, said the sergeant wasn’t immune to mistakes despite what he said was his distinguished 20-year career.

“He made a series of wrong choices,” he said.

Pleines advocated for the 60-day suspension sought by the superintendent.

jgorner@tribune.com