John Joseph Brown, 60, on Wednesday pleaded not guilty to first-degree murder, robbery and kidnapping in 51-year-old Barker's death.
Six others have been charged in the case. Five of them - William Barry, 33; Angela King, 32; Aileenah Horton, 17; Justin Mahaffey, 23; and Joshua Stevens, 23 - have pleaded not guilty to charges of premeditated murder, kidnapping and burglary. They are being held on $2 million bail each.
One suspect remains at large. Investigators have issued a nationwide alert for Jeffrey W. Powell, II, who has been charged with first-degree murder, first-degree robbery and first-degree kidnapping. A warrant has been issued for his arrest.
Brown told investigators the brutal assault on the victim took place at his home. He said the defendants beat Barker for nearly two hours before taking him from the home and killing him.
When questioned by investigators, several of the suspects said they abducted and beat Barker because they believe he had molested a toddler, according to the statement of probable case. One suspect claimed Barker had also sexually assaulted a woman.
However, Pierce County Prosecutor Mark Lindquist said the suspects' claim of vigilante justice for the victim's alleged sex crimes may not be true as investigators have not found any evidence to support either claim.
"Why wait until weeks after the alleged sexual assault? Why take the victim's watch? Why steal the victim's money?" said Lindquist. "What we know is that all the defendants were involved in a robbery and kidnapping at defendant Brown's house that led to murder."
After the beating, the suspects took Barker's wallet and split the cash, they told investigators. They also tied a red bandanna around his neck to "mark him, as Mahaffey belongs to a blood gang, the statement said.
Horton said she participated in the beating, but did not accompany the others to the home where the victim was abandoned. King said she went to the Graham home, but stayed in the car while Mahaffey and Powell walked Barker out of the car. She said Barker was still alive when she and Mahaffey left the scene.