BOISE - An Idaho Republican Party leader who helped oust the state GOP chairman in 2008 faces charges of aggravated assault with a deadly weapon after an altercation escalated while he photographed a home with a delinquent mortgage.

Challis McAffee, 33, the GOP chairman from the Boise suburb of Garden City and one of 231 voting members of the Idaho Republican Central Committee, was in Ada County Jail after being accused of pointing a gun at the homeowner.

McAffee works for a contractor hired by Wells Fargo & Co. to document the condition of homes where mortgages are past due or in foreclosure. A Wells Fargo spokesman condemned McAffee's behavior, calling it "horrific and absolutely inexcusable."

McAffee, a backer of libertarian-leaning former GOP presidential candidate Ron Paul and an activist in this year's anti-big-government "tea party" protests, helped organize Paul backers who aligned at last June's Idaho State Republican Convention in Sandpoint with other foes of then-state GOP Chairman Kirk Sullivan. Sullivan was voted from office in favor of Norm Semanko.

According to police in the Boise suburb of Meridian, resident Robert Lutes called officers just before 5:30 p.m. Tuesday to report McAffee had pointed a .357 Magnum handgun at him during a verbal confrontation. McAffee acknowledged he pointed the gun at Lutes, according to the police account.

"I'm unarmed, I'm an old man," Lutes, 51, told The Associated Press on Thursday. "I'm trying to find out why he's taking pictures of my house. I said, 'Knock on my door, let me know what you want.' Then I think he's reaching for his business card and he pulls out a concealed weapon, and I think he's going to blow my head off."

Lutes said the gun was beneath a cloth on the floor of the passenger side of McAffee's vehicle.

The Idaho Republican Party said the arrest of one of its southwestern Idaho leaders was a "personal matter."

"It's not a party matter," said Jonathan Parker, state GOP director in Boise.

McAffee couldn't immediately be reached in jail.

Ryan Davidson, another Paul supporter who has gained attention by pushing pro-marijuana voter initiatives in the central Idaho town of Hailey, said McAffee told him a different version of the altercation in a phone call from jail.

Lutes confronted McAffee, becoming increasingly hostile, Davidson said. When Lutes struck McAffee's Ford Escort with his hand, McAffee brandished the weapon to de-escalate the conflict, Davidson said.

"Challis is one of the most mild-mannered, good-natured guys," Davidson said. "The conversation wasn't going anywhere; the guy smacked the car window. At that point, he (McAffee) felt threatened enough, he picked up the firearm in front of the seat that he carries for protection. The nature of the job is, you're going to run into some unhappy people."

Davidson has sent messages via Ron Paul e-mail lists in hopes of collecting the $50,000 needed to post bail for McAffee, whose arrest was originally reported in the Idaho Statesman.