Michelle Mockbee's Killer Had Two Trials, With Different Defense Strategies

Michelle Mockbee, by all accounts a hard-working and lovable mother of two, lost her life with little warning on May 29, 2012, as she went about her business as usual.

Murdered most likely for threatening to expose an ex-con who was skimming off the scientific equipment company they both worked at, Michelle left behind a gaping void in her family and community. After a four-week trial, her killer was sentenced to life. The family’s ordeal, however, was not over.

Veteran prosecutor and television analyst Nancy Grace relates the story of Mockbee — and her killer’s two trials — on the latest episode of “Injustice With Nancy Grace,” which airs Saturdays on Oxygen.

David Dooley, a janitor at Thermo Fisher Scientific in Boone County, Kentucky, was found guilty in 2014 of killing Mockbee, and sentenced to life in prison. Prosecutors and investigators said that Mockbee caught Dooley in the act of trying to cover up his and his wife’s “triple-dipping” scheme, falsifying timecards to be paid for work they didn’t actually do.

“Knowing Michelle, she was pretty blunt,” Tom Siemen, one of Mockbee’s former coworkers, told “Injustice” producers. “I think it escalated.”

It escalated indeed. Mockbee was beat over the head with an industrial tape dispenser. She suffered “at least four devastating blows to the head,” a former medical examiner testified at Dooley’s second trial, according to local NBC station WLWT5. Mockbee’s arm was also broken, possibly while she was unconscious, as she was dragged 40 feet to where her body was eventually found.

The modicum of closure Mockbee’s family felt after Dooley’s conviction was short-lived, however, when prosecutorial misconduct was alleged, according to a 2017 WCPO Cincinnati report. A judge later found that evidence had not been withheld deliberately, according to a later report.

A circuit court judge allowed for a new trial, which began in 2019. What did Dooley’s defense team do differently this time, though?

For starters, they cast a wide net, alleging that there were others who could have killed the mother of two — including Mockbee’s husband, Dan.

"They said that David Dooley had the opportunity to do it. Of course he did," defense attorney Deanna Dennison said during opening arguments at the retrial, according to WCPO. "He had the opportunity to do it, because he's walking around the building doing his janitorial duties, but there are other people in that warehouse, that also had the opportunity to do it too, that were completely ignored."

Dennison’s team questioned Dan Mockbee about his personal finances, according to the Cincinnati Enquirer — including the life insurance money he received after his wife’s death. They asked Dan, at one point, if he had anything to do with hiring someone to kill his wife.

Defense attorneys also cast doubt on the testimony of one of Michelle’s coworkers, Joe Siegert. Dennison pointed to a 20-minute discrepancy between Siegert’s testimony at the first trial and the retrial, according to the Enquirer. Siegert had testified that he saw Dooley and Michelle both on the morning of her murder.

A surveillance video that showed at least one man walking around the Thermo Fisher Scientific building the evening before Michelle’s murder — and which the defense claimed was kept from them during the first trial — was also played for the jury during the retrial. However, a Boone County detective walked the jury through the video, and appeared to dismiss its significance, according to the Enquirer.

The detective said that the man in question was really “nowhere near” the entrance to the Thermo Fisher building, the Enquirer reported, although the defense still argued that the man could have gone elsewhere around the building, due to the lack of additional cameras.

Still, the second jury was apparently unmoved by the defense’s new strategy. They found Dooley guilty after another four weeks of witness testimony and eight to nine hours of deliberating, a former prosecutor said on the show.

“Once there was another guilty verdict, it was just a huge relief to me, to our entire family,” Michelle’s sister, Jennifer Schneider, told “Injustice” producers. “Now a second jury saw the facts and found him guilty.”

Dooley was sentenced to 38 years for the murder, plus five for tampering with physical evidence, on April 11, 2019.