They opted for second degree murder and the father and daughter now face 20-25 years in jail.
Molly Martens, 33, and hcer father, former FBI agent Thomas Martens, 67, beat Jason Corbett to death with a baseball bat and a concrete paving brick.
Mr Corbett, 39, was found bludgeoned to death in the master bedroom of his house at 160 Panther Creek Court in the Meadowlands, a golf-course community in Davidson County in the early hours of August 2, 2015.
He lived there with Ms Martens, his second wife, and his two children from his first marriage, Jack and Sarah.
He met Molly in 2008 when he hired the American as an au pair for Jack and Sarah and the two soon began dating, culminating in a marriage in 2011.
The prosecution said Mr Corbett was beaten so badly that pieces of his skull fell out on the medical examiner’s table during the autopsy.
“You’re going to see pieces of his skull that look like a hard boiled egg that got dropped on a counter,” said Assistant District Attorney Alan Martin during a graphic recounting of the prosecution’s case.
“There was blood on this wall and there was blood on this wall,” Mr Martin said, pointing to various parts of the courtroom as if it were the master bedroom Mr Corbett was found in.
He said blood was everywhere in the bedroom, along the hallway and in the bathroom nearby. A baseball bat and a brick paver were covered in blood.
Mr Corbett, Ms Martens, and Mr Martens were the only ones in the bedroom and in the bathroom, but the Martens came out without any visible wounds, said Mr Martin.
He said Mr Martens struck Mr Corbett with the baseball bat and Ms Martens hit her husband with the brick paver.
David Freedman, one of Martens’ attorneys, described to jurors a struggle in which Mr Martens and Ms Martens feared for their lives.
Staying at his daughter’s home, Mr Martens woke around 3am when he heard screams.
“He knows upstairs is his daughter,” said Mr Freedman. “He knows upstairs is his grandchildren. He doesn’t know what he’s facing.”
Mr Martens, said Mr Freedman said, grabbed a little league baseball bat that he had planned to give to Jack the next day and ran up the stairs. He went to the bedroom and found Mr Corbett choking Ms Martens, said Mr Freedman.
Mr Martens told him to stop, and Mr Corbett threatened to kill Ms Martens. He moved out of the bedroom and toward the bathroom, Freedman said.
Mr Martens hit Mr Corbett until he let go of Ms Martens and fell down in the bedroom. Then Mr Martens called 911 and performed CPR, said Mr Freedman.
However, a dispatcher who took the Martens’ 911 call said Mr Martens never sounded out of breath, even as he did three rotations of CPR on Mr Corbett.
Karen Black Capps, a dispatcher in Davidson County for the past 16 years, said CPR is exhausting and many people who perform it are often out of breath.
“I noticed he was not out of breath,” said Ms Capps. “He didn’t sound like most people do.”
Medical examiner Craig Nelson, said Mr Corbett had 10 different impact sites on his head that indicated blunt force trauma. Two of those impact sites showed complex lacerations that indicated Mr Corbett was struck more than once.
Blood spatter expert Stuart James examined 700 crime scene photos, Mr Corbett’s autopsy report, autopsy pictures, and other evidence to evaluate blood found on the walls, floor, bedcovers and other places in the master bedroom.
Mr James said he saw a number of what he called impact blood spatters, which are created by violent force. On the south wall of the bedroom, he saw blood spatter at different sections, along with what appears to be small dents in the wall, suggesting Mr Corbett hit his head as he was falling down.
Another pattern of blood indicated transfer blood, showing that Mr Corbett was moving to the hallway.
Mr James said he saw impact blood spatter on certain spots of Mr Martens’ shorts that would indicate that he was just above Mr Corbett when Jason was struck.
Despite the bloody scene, the court heard, Molly and Thomas Martens had no visible signs of injury on the morning Mr Corbett was bludgeoned to death.
Captain Clayton Dagenhardt of the Davidson County Sheriff’s Office said he received a call about a cardiac event just after 3am on August 2, 2015. Two minutes after receiving that call, he received another call saying it had been upgraded to an assault. He got to the house about 3:16 a.m.
He saw a paramedic that he knew coming out of the house, and that paramedic told him: “It’s bad. It’s really bad. It’s a horrible scene.”
Capt Dagenhardt said he walked into the house, took a left and went into the master bedroom where Mr Corbett was found.
He saw the body on the floor, face up. He saw blood on his face around his eye and blood on several areas of his body. He also saw blood on several of the walls, including walls leading to the master bedroom’s bathroom.
He said he and another officer went to collect Jack and Sarah, who were asleep upstairs in bed.
Capt Dagenhardt said he woke Sarah and led her backwards down the stairs and told her to keep her eyes closed. He ended up carrying her.
In other testimony, Joanne Lowry testified that she worked with Mr Martens at Oak Ridge Laboratory in the Counterintelligence Office for at least eight years.
Ms Lowry, who has since retired, had one of the highest security clearances from the US Department of Energy to handle sensitive foreign traffic. The clearance meant she had access to classified information.
She worked with Mr Martens daily. One Monday, about two months before Mr Corbett was killed, she sat beside Mr Martens and asked him how his weekend was.
She said that, after speaking of the children, Mr Martens told her: “That son-in-law... I hate him.”
She also testified that Mr Martens expressed his dislike of Mr Corbett in 2011 ahead of his wedding to Ms Martens.
“It was just a discussion of his pre-wedding celebration,” she said. “He indicated his dislike for Jason and his rowdy friends.”
Ms Lowry said Mr Martens did not explain his statements in 2015 and 2011.
Questioned by David Freedman, Mr Martens’ attorney, Lowry said she could not remember exactly when in 2015 Martens made the statement about Jason Corbett.
She also said under cross-examination that Mr Martens had been in a good mood but that his attitude had changed when he mentioned Mr Corbett.
The Martens’ legal team took the prosecution case apart piece by piece.
Investigators, they said, failed to collect and test certain evidence, such as a hair on Jason Corbett’s hand that might have corroborated Molly Martens’ story that he had choked her.
David Freedman and Jones Byrd pointed out that she told emergency workers that her throat hurt and she had trouble swallowing.
They argued the physical evidence actually corroborated Thomas Martens’ version of events — that he struck Mr Corbett to protect his daughter.
Mr Byrd said the jury should be concerned about everything it did not see — the recorded statements from the Martens, for example.
He said Stuart James, the blood-stain pattern expert, couldn’t even be bothered to go to the house or review reports from paramedics. Mr James did not use accurate diagrams of the house when drawing his conclusions, alleged Mr Byrd.
Investigators also failed to take pictures of Mr Martens in the plaid boxer shorts he was wearing, it was claimed. The only pictures of Mr Martens were taken over four hours later at Davidson County Sheriff’s Office where he gave a voluntary statement.
“He doesn’t have to prove one thing to you,” Mr Byrd said about Mr Martens. “It’s their [prosecutors’] burden. They want to use their lack of evidence against him. Folks, don’t let them do that.”
Mr Freedman said Mr Martens fought to protect himself and his daughter.
“Tom Martens woke from a dream into a nightmare sometime before 3am, Sunday, August 2,” he said. “Before he heard noises, he thought he was there to visit his grandchildren, his daughter, and his son-in-law.”
Once he heard the noises, he grabbed the metal baseball bat he had planned to give Jack, one of Mr Corbett’s children from his first marriage, the next day and went upstairs.
“He spent his life defending our country... he has served us. He has protected us,” said Mr Freedman. “That’s what Martens knows how to do, to protect.”
The last thing Mr Martens would ever expect to see is his son-in-law with his hands around his daughter’s throat, said Mr Freedman.
Mr Martens did what he had to do to protect his daughter; not exact revenge on Jason for smoking and drinking at a pre-wedding celebration at his house in 2011, said Mr Freedman.
He noted that Mr Corbett had been diagnosed with depression and had a thyroid condition that he was not taking medication for. He also had seven beers, he said.
Two weeks before he died, Mr Corbett said he was stressed and becoming angry for no reason, alleged Mr Freedman.
Prosecutors kept mentioning the number of blows — at least 12 to the head — as proof of excessive force, said Mr Freedman. It is not, he argued.
Every time the bat hit the table, the jury flinched.
Assistant District Attorney Alan Martin banged the 70cm Louisville Slugger baseball bat again and again. This, he said, was what Thomas Martens used to beat Jason Corbett with.
Later, he slammed a concrete paving brick that prosecutors allege Molly Martens used to strike Mr Corbett with.
Addressing the jury and and pointing at Mr Martens and Ms Corbett, he said: “They killed him.
“He killed him with a bat. She killed him with that brick.” They did it without justification, without legal excuse.”
He then went through the gruesome crime scene and autopsy photos.
“They literally beat the skin off his skull with that bat and that brick,” he said.
“They, acting in concert, her and him, literally crushed his skull, turned it into something that looked like a bad Humpty-Dumpty cartoon.”
Mr Martin said the physical evidence suggested that not only did Ms Martens and Mr Martens use excessive force, but that they tried to cover it up.
He said Mr Martens waited two minutes before calling 911. Mr Martens testified that he waited two minutes to collect himself and there were several more minutes while Ms Martens found a phone so he could call 911.
Mr Martin said Ms Corbett was not strangled, as she had claimed. Mr Martin also questioned why Sharon Martens, Ms Martens’ mother and Mr Martens’ wife, never heard anything or called 911, if there was indeed a life-and-death struggle going on as described by Mr Martens.
“Jason did not have to die,” Mr Martin said. “He did not have to die in his own bedroom. He did not have to die with his children at the top of the steps.
“He did not have to die at the hands of the woman he came to America for. He did not have to die at the hands of her father... You have a duty to return a verdict that will deliver justice for Jason.”