COEUR d'ALENE - Federal prosecutors and Sagle resident Larry Fairfax, who was allegedly hired by Edgar J. Steele to kill Steele's wife, have both signed a plea deal, according to court documents filed in U.S. District Court here.

The documents say he'll plead guilty to one count of possession of an unregistered firearm, and a count of making a firearm in violation of the National Firearms Act. The firearm in this case was a large metal pipe bomb, which was found under Cyndi Steele's vehicle during an oil change in June.

Both counts carry a possible 10-year prison sentence.

A change of plea hearing is scheduled for Sept. 7. The court is not bound by the agreement.

The 14-page plea agreement document alleges that Fairfax and Edgar Steele, an attorney who has represented multiple high-profile clients, had several conversations between November 2009 and June 2010 in which they discussed Fairfax killing Cyndi Steele and her mother.

The document says that if the case proceeded to trial, prosecutors and Fairfax agree he would be proven guilty beyond a reasonable doubt. Fairfax and his defense attorney, John Miller, signed the plea agreement.

The documents say Edgar Steele also had Fairfax put a pipe bomb under Steele's own vehicle that he could explode, providing him with an alibi after the other pipe bomb exploded under his wife's vehicle.

Fairfax made the pipe bombs, and attached them to Cyndi Steele's and Edgar Steele's vehicles in late May. A day or two later, Cyndi Steele drove her vehicle to Oregon to take care of her mother.

"The device did not explode and Steele demanded explanation from Fairfax as to why the plan did not work," according to the documents.

Fairfax and another individual, not identified in the documents, drove to Oregon to check whether the pipe bomb was still on her vehicle. They didn't see it and returned to Idaho assuming it had fallen off.

Fairfax then removed the device from Edgar Steele's vehicle, the documents said.

Steele was arrested June 11, and was indicted June 15 on a charge of murder-for-hire. Steele has pleaded not guilty, and a trial is scheduled for November.

On the day of the indictment, Cyndi Steele stopped for an oil change in Coeur d'Alene when employees at a lube station discovered the pipe bomb. The discovery shut down U.S. 95.

Fairfax has not been indicted by a grand jury, but prosecutors did file charges in a criminal complaint against him.

In testimony during a detention hearing for Fairfax in June, it was revealed that Fairfax was the alleged hitman, and that he had cooperated as an informant who told authorities about Edgar Steele's alleged murder-for-hire plot. Testimony revealed that Fairfax wore a hidden recording device in meetings with Steele.