A suspended Chicago police officer wanted a former fellow cop — a potential witness against him — killed and considered hiring street gang members to do the "paint job," a code for murder, according to a federal complaint filed Wednesday.

Jerome Finnigan, 44, is quoted in an FBI agent's affidavit as telling a co-defendant he was looking for someone less risky than gang members, but warning the cost would go up for "professional painters."

Finnigan is one of six members of an elite Chicago police unit already accused of using their badges to shake down residents and intimidate people. He faces state charges including armed robbery and aggravated kidnapping in that case proceeding through Cook County criminal court.

A federal investigation of the special operations section of the police department — which focuses on drugs and gangs — also is under way.

According to federal authorities, the man targeted for death could be a witness against Finnigan in both the federal investigation and the ongoing state criminal prosecution.

"The gravity of this conduct speaks for itself," U.S. Attorney Patrick Fitzgerald said in a statement.

A message seeking comment was left Wednesday for Finnigan's attorney.

Finnigan, who is free on $4 million bond in the state cases, was arrested at his home on the city's southwest side Wednesday morning by FBI agents, authorities said. An afternoon court appearance was planned.

He is charged with using a telephone to commit murder-for-hire. In a case such as the one against him, where no death or injury occurs, the charge carries a maximum penalty of 10 years in prison and a $250,000 fine, authorities said.

According to the affidavit submitted by FBI special agent Tom Simon, Finnigan had learned that a former Chicago Police officer — labeled cooperating witness 1 by Simon — would be a witness against Finnigan in the first of the state cases to go to trial.

This summer, Finnigan began discussing with a co-defendant in the state case the possibility of hiring gang members who would kill CW1 for $5,000, using the term "paint job" as code, according to Simon's affidavit.

The co-defendant eventually began cooperating with federal authorities, and recorded some of their conversations.

In one transcript reproduced in the affidavit, Finnigan allegedly told his co-defendant that one man he had talked to "has done a lotta paint jobs."

But the co-defendant told authorities Finnigan also encouraged him to try himself to find someone to kill the former officer and potential witness.

When the co-defendant said last Friday he had found someone to do the job, Finnigan gave him a photograph of CW1, described his vehicle, agreed to pay half the fee for a hit man and said he would provide his co-defendant with CW1's current address, according to the affidavit.