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Michelle Mockbee left for work early the morning of May 29, 2012 just like she had so many other days before.
But this would be the Kentucky mother of two’s final shift.
Michelle, the head of payroll at ThermoFisher Scientific warehouse, was discovered dead early that morning lying face down in a pool of blood on a mezzanine not far from her office.
“I had never been around anything like that,” David Dooley, a janitor who discovered the body alongside a company supervisor, told “Dateline: Secrets Uncovered," airing Thursdays at 8/7c on Oxygen. “It was kind of frightening for me.”
It wouldn’t take long for investigators to zero in on their primary suspect, but even after an arrest was made, Michelle’s case would be far from over.
Two of the key players who helped put the suspected killer away would soon find themselves under intense scrutiny about their own personal entanglements and what they had revealed in court about the case — and what they hadn’t.
Michelle had seemingly been living a wonderful life before it was cut brutally short. Much of it centered around the very place where she’d lose her life.
It was at the laboratory equipment company that Michelle met her future husband, Dan Mockbee.
“The world just totally changed,” Dan told “Dateline: Secrets Uncovered” of meeting Michelle. “The sun got brighter. It was just a totally different world.”
The couple married in 2001 and went on to have two daughters together, Madelyn and Carli.
“Michelle was just the most amazing sister that you could ever ask for. Very loving, caring, giving person, she would do anything for anyone,” her sister Jennifer Schneider told investigative reporter Josh Mankiewicz.
Despite their busy life, Michelle and Dan — who both still worked together at ThermoFisher Scientific — made it a point to have regular date nights. Their final date was on Memorial Day 2012, the night before Michelle would be found bludgeoned to death at work.
If Michelle had anything on her mind that night, Dan said it wasn’t noticeable.
The next morning, Michelle woke up early and kissed him goodbye before she left for work, he’d later tell “Dateline: Secrets Uncovered.”
She’s captured on surveillance footage arriving at the warehouse at 5:53 a.m. An hour later, a supervisor at the company noticed a stain on the carpet and went to investigate alongside Dooley. The pair discovered Michelle dead with a plastic bag over her head.
Investigators would discover pry marks on the door to her office, suggesting that someone may have been trying to break into the room.
Dan raced to the warehouse and was escorted inside by Detective Everett Stahl, who delivered the crushing news.
“His reaction was pretty excruciating to watch,” Stahl would recall. “I still had to press on and I still had to move forward with my looking at him as a possible suspect.”
But investigators were able to quickly rule Dan, who told authorities he had been at home sleeping, out after he passed a polygraph test.
They then focused instead on the 13 employees who had been at the warehouse at the time. Surveillance footage revealed that just one of those people had left the property for a brief period of time: Dooley, the janitor who had been one of the people to find Mockbee dead.
Dooley’s truck was seen leaving the property at 6:31 that morning and returning to the property around 7 a.m.
Dooley told investigators he had gone back to his apartment because he couldn’t get a hold of his wife and wanted to make sure she was OK, but when police asked his wife, it seemed that she initially told investigators that he hadn’t come home that day, although the taped conversation is difficult to make out.
She later told law enforcement authorities in a taped interrogation room that Dooley had come home to change his pants. Dooley himself denied ever changing his pants and insisted that his wife must have misheard him.
Investigators grew even more suspicious after they realized that Dooley and his wife, who also worked at the warehouse, had been stealing from the company by checking each other in on their time cards for time when they weren’t at work.
“Our belief has always been that David Dooley was in the middle of breaking into her office when she came up the steps and surprised him and ultimately, she was assaulted and restrained,” prosecutor Linda Tally Smith told the show.
The medical examiner would later testify that he believed Mockbee was bludgeoned to death with an instrument similar to dan industrial packing tape gun.
Authorities executed search warrants on Dooley’s property but were never able to find any bloody clothes or the weapon used to kill Mockbee. Even without that critical evidence, investigators believed they had enough to link him to the crime and made an arrest on Sept. 27, 2012.
Dooley continued to maintain his innocence, and the defense team was quick to point out that unknown DNA had been found on Mockbee’s body that didn’t match the former janitor, but a jury convicted him of the murder in 2014.
It seemed as though the case had been resolved, until two years later when a whistleblower came forward to reveal a scandalous affair between Smith and lead detective Bruce McVay, that had reportedly begun weeks after the trial concluded.
The conviction soon came under scrutiny, particularly after personal correspondence during a breakup between Smith and McVay revealed that McVay had never disclosed information about the investigation during the trial. He neglected to discuss surveillance footage that captured an unknown man wandering on the warehouse property the day before the killing.
“Now that I know what a complete [expletive] liar you are, I am going to grapple with [expletive] ethical issues with every case in which you were involved,” Smith wrote him in an 18-page letter that she never ended up sending.
It went on to accuse McVay of letting her “go through a complete [expletive] murder trial without telling me the truth about that video,” and questioned what she should do now that she was aware of the footage.
Prosecutors claimed they had given Dooley’s defense attorneys the footage, but his legal team insisted they had never seen it or they would have used it during the trial to point suspicion away from their client.
After hearing testimony during a hearing from both Smith and McVay, a judge threw out the conviction against Dooley and ordered a new trial.
Kentucky Assistant Attorney General Jon Heck took over the case for the prosecution and decided to address that controversial video footage head on. He said the man in question only walked up to the building for mere seconds to throw something away in a garbage can before walking away from the building.
He believed Dooley was the only suspect with the means, opportunity, and motive to kill Mockbee.
“This was a bloody, violent murder. They would be covered in blood. There were no bloody clothes found on the scene. Whoever did it left and when you looked at the video camera, he’s the only one who left,” Heck said.
He also pointed out that Dooley’s steel toed work boots had never been found and neither had the time cards for Dooley and his wife that week that showed he had been stealing from the company. Investigators did find, however, a screw driver locked within Dooley’s locker that was the same size as the marks left on the office door.
Although Heck couldn’t provide a definitive reason for why Mockbee was killed, he believed it was likely because of the couple’s payroll scheme.
Dooley’s defense attorneys Deanna Dennison and Jeff Lawson were quick to fire back, pointing suspicion toward other potential suspects including that man seen walking on the surveillance footage.
They even pointed suspicion toward Michelle’s husband, Dan, who they said stood to cash in on a large insurance policy and made a series of large cash withdrawals after his wife was killed.
“We started seeing cash withdrawals, $10,000, $20,000, $12,000, $14,000,” Dennison said. “[It] suggests that there’s something wrong. $409,000 in cash withdrawals, could he be paying somebody? I don’t know.”
But even with the possible new suspects in the case, a new jury would reach the same conclusion and convict Dooley once again of the murder.
He was sentenced to 43 years behind bars.
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