Officer Joseph Finnigan of the Chicago Police Department has been charged with plotting the murder of a fellow officer who was supplying information about him to a corruption investigation.

He was reportedly charged after discussing the murder plans with another officer who was wearing a wire for the investigators.

The Chicago Tribune says that the officers discussed whether to hire a gang member or a professional hitman to do the job.

Finnigan, 44, was being investigated in a probe of kidnapping and robbery associated with the department’s Special Operations Section, which polices high crime areas and focuses on drug and gang arrests.

“The complaint charges that in the face of serious pending state charges and a federal investigation that could result in additional charges, the defendant solicited the murder of a fellow police officer who he believed would be a witness against him,” U.S. Atty. Patrick Fitzgerald said. “The gravity of this conduct speaks for itself.

Authorities say that Finnigan and the wired officer discussed killing up to four other officers.

Finnigan was arrested outside of his Chicago home. A bond hearing is scheduled for Monday.