Kehoe and Danny Lee Graham, 24, of Oklahoma City were charged in Pope County, Ark., in the deaths of William Mueller, 52; his wife, Nancy, 28; and Mrs. Mueller's daughter, Sarah Elizabeth Powell, 8, Pope County Sheriff Jay Winters said.
Canadian County Sheriff Lewis Hawkins said he took Graham into custody as he was shaving at his home.
Kehoe, 24, and his brother, Cheyne Kehoe, 21, were accused in two shootouts with law enforcement authorities that occurred minutes apart Feb. 15 in and near Wilmington.
One of the shootouts was captured on an Ohio Highway Patrol trooper's dashboard camera. Kehoe is being held in Warren County Jail pending a Dec. 8 trial.
Winters said Graham and Chevie Kehoe were each charged with three counts of capital murder, which carries a possible death sentence in Arkansas.
Graham appeared before a Canadian County judge a short time after his arrest and refused to waive extradition to Arkansas. Hawkins said Graham would be charged as a fugitive from justice and Arkansas authorities would have a 90-day window to extradite him.
The decomposed bodies of the Muellers and the girl were found in June 1996 in the Illinois Bayou in Arkansas.
Authorities believe the family, who lived near Tilly, Ark., were killed elsewhere and their bodies dumped in the bayou. The Muellers were last seen alive the night of Jan. 9 by a family friend who was visiting them at their rural home. They apparently disappeared while on their way to a gun show.
Chevie Kehoe made his living trading and selling guns at shows. He was indicted by a federal grand jury in Spokane, Wash., in February on three firearms violations. He is accused of possessing a pistol stolen from Mueller in October 1995 and a .223-caliber rifle taken from Mueller when the gun dealer disappeared in 1996.
Hawkins said Graham, who has been jailed in Oklahoma, Tennessee, Florida, Washington and Wyoming, has an extensive criminal history including arrests for homicide, robbery, resisting arrest, theft and assault with a dangerous weapon.
The sheriff did not know the outcome of the various charges filed against Graham.
``He has been around in his short time,'' Hawkins said. ``How come people like this are out on probation and reporting to a parole officer rather than being in prison, I don't understand.