BOONE COUNTY COURTHOUSE -- The Hallsville man accused of murdering his ex-brother-in-law at a Columbia McDonald’s finished testifying in his own defense on Thursday morning.

Billy Clinch, 39, admits he shot and killed Jeremy Bohannon, 32, two years ago.

Clinch says he killed Bohannon in order to save the lives of Bohannon’s three children who are also Clinch’s nieces and nephew. 

Clinch testified that he lived in constant fear for his sister Mandy and her three children because Bohannon was an "abusing monster" who had to be stopped. 

Prosecutors say Clinch had an incestuous affair with his sister Mandy who was also Bohannon's wife. Investigators say Clinch murdered Bohannon out of jealousy. Boone County Prosecutor Dan Knight showed jurors a picture of Clinch with his sister Mandy sitting on his lap while she was married to Bohannon.

Knight asked Clinch, “She’s got her hand on top of your hand, doesn’t she?" "She does," said Clinch. 

Knight than asked,"She’s sitting right on your lap. Correct? Is that the way you often sat down with Amanda with her right on your lap like that?" "No, answered Clinch. "Just in that picture? Only that one event?" asked Knight. "That’s the only picture I’m aware of out of all of the pictures we’ve had like that," said Clinch.

Clinch’s public defenders told jurors that Clinch never had a sick, twisted relationship with his sister Mandy. After Clinch finished testifying for a two day total of about 13 hours, Public Defender Jennifer Bukowsky called Clinch’s cousin to the stand to support accusations of abuse by Bohannon. 

Kelley Cordray told a story of how Bohannon frightened his son Joey.

“Joey was running around in circles," Cordray said through tears. "He was scared to death. He didn’t know what to do. He was running back and forth to everybody. I finally said, Joey come here. I picked him up and he was shaking so hard that I thought he was having a seizure.”

Clinch faces a charge of first-degree murder. Prosecutors say Clinch was planning to kill Bohannon for about a year-and-a-half before he actually gunned down his ex-brother-in-law. Clinch’s trial is expected to last through next Tuesday.

If convicted of first-degree murder, Clinch could face life in prison.