David Edenfield, 61, faces the death penalty if convicted of the March 2007 slaying of Christopher Michael Barrios, whose body was found in a trash bag dumped near a road.
On the second day of Edenfield's trial, jurors watched the second hour of a taped interview the suspect gave to a Glynn County police detective the day after Christopher's body was found.
On the tape, Edenfield says he and his wife watched their son, 34-year-old George Edenfield, strip the boy and force him to have sex on a bed in their mobile home while the child pleaded for them to stop.
"It's my fault. I should've been a grown man and stopped it right then, but I didn't," the elder Edenfield tells detective Raymond Sarro on the tape. "I should be punished for the crime."
Edenfield said he pulled his pants down and rubbed himself against the boy, but denied having sex with him. He said his son started choking Christopher after the boy cried out "I'm going tell my daddy and grandma!"
Instead of stopping his son from killing the boy, Edenfield says he placed his own hands on top of his son's while they were around Christopher's neck.
"I put my hands on his hands, but I did not squeeze," Edenfield says on the recording. "I just wanted to see what it would feel like, I guess."
"What what felt like?" Sarro asked.
Edenfield replied: "To choke somebody."
James Yancey, one of Edenfield's lawyers, said as the trial opened Wednesday that the taped confession was influenced by the police interrogators, but stopped short of telling jurors his client was coerced.
Edenfield is the first suspect to stand trial in the slaying. His son and wife, Peggy Edenfield, have also been charged with molesting and killing the boy, then hiding his body. Because of pretrial publicity, the jury was selected from residents who live some 90 miles away, and the jurors are being sequestered in Brunswick, 60 miles south of Savannah.
Barbara Retzer, a forensic biologist with the Georgia Bureau of Investigation, testified Thursday that swabs taken from Christopher's body were tested for DNA and compared with blood samples from all three Edenfields. She said all tests came back negative. Tests for semen also were negative.
Retzer noted that heat and humidity can degrade DNA over time. Police believe Christopher's body was left outside for a week.
Christopher lived in a Brunswick mobile home park where his father and grandmother had homes. He would pass the Edenfields' trailer when walking between them.
The Edenfields moved into the mobile home park where the boy lived just a few months before his death. The family had been forced to move because George Edenfield was a convicted child molester. The family's previous home was close to a playground, a violation of Georgia's sex offender registry law.
In an earlier police interview from March 2007, also shown to the jury, Edenfield acknowledged he had been charged with incest in 1994, when he was accused of having sex with an adult relative who was not his son.
Edenfield pleaded guilty to the charge, but in the police interview he denied wrongdoing. He said the relative was angry with him and made up the accusation.
In that interview, conducted three days before police found Christopher's body, Edenfield insisted his family had no involvement with the missing boy. He also said he couldn't believe his son would have hurt the child.
Edenfield told investigators: "He loves children to death."