TAMPA — Adam William Davis, who in 1998 murdered his teen girlfriend’s mother, will no longer face execution but will spend the rest of his life in prison.
More than two decades after the slaying of Vicki Robinson, Hillsborough prosecutors said Thursday they will no longer try to keep Davis on death row. They cited his youth, his mental health, the sentencing disparity between Davis and his fellow defendants, and the fact that his jury voted by a bare majority for a death sentence.
The non-unanimous jury vote was what opened the door to a new penalty hearing for Davis. He was one of dozens of death row prisoners whose sentences were overturned after the U.S. Supreme Court in 2016 struck down Florida’s death penalty law as unconstitutional.
Florida previously was one of the only U.S. states to allow juries to be less than unanimous in recommending the death penalty. For years, seven votes for death on a 12-person jury was all it took. But after the high court weighed in, state legislators rewrote the law to require that juries be unanimous in death cases going forward.
Davis, 42, returned to the Hillsborough jail this month ahead of what was expected to be a lengthy new penalty hearing. A court had prepared to assemble a new jury to decide his fate. Attorneys later agreed to have a judge alone hear the case. It was set to be heard Monday.
But amid last-minute mitigation efforts by the defense, prosecutors decided to leave Davis with a life sentence.
“This was a horrific murder with serious aggravating factors, but Davis was only 19 at the time— which gives us tremendous pause,” Hillsborough State Attorney Andrew Warren said in a statement. “The fact that he had mental health issues, that his coconspirators received much shorter sentences, and that the original jury recommended death by the slimmest margin — 7 to 5 — further weighs against the death penalty. These are difficult decisions, but in cases this close, we opt for life in prison.”
Rick Terrana, who handled Davis’ defense at trial and took it up again for the new penalty phase, said he got word Wednesday of the state’s decision.
“We certainly applaud the state attorney for having the intellectual wherewithal and the fortitude to make a decision that, though not the popular decision, will certainly be legally correct and, more importantly, just the right and fair decision,” Terrana said.
In the last two years, Terrana said he has assembled extensive mitigation evidence, which he presented to the state. It included opinions from no less than five psychological experts, who were prepared to testify about neurological impairments Davis suffered.
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“The likelihood of achieving a 12-0 vote for death was, in my opinion, little or none,” Terrana said.
Davis has lived on death row since 2000. Like other condemned prisoners, he has experienced little beyond the dark bars of a small cell at Union Correctional Institution, where he is confined for about 23 hours a day.
With a life sentence, he will join the state prison system’s general population.
He already had a criminal history when the murder occurred. He dated 15-year-old Valessa Robinson, whose mother, Vicki Robinson, had struggled to control her daughter’s rebellious behavior.
On the evening of June 26, 1998, Valessa snuck out of her mother’s home and went with Davis and another teen, Jon Whispel, to a Denny’s restaurant. The trio later bought and took LSD, then returned to the restaurant. It was then that Valessa suggested that they should kill her mother, according to case records. Whispel later said he thought she was joking. But she and Davis began plotting.
Their plan originally was to inject Vicki Robinson with a lethal dose of heroin, according to case records. But unable to obtain the drugs, Davis decided to use bleach instead. Later that night, he attacked Vicki Robinson in her kitchen, then used a syringe to inject her. When she didn’t die, he stabbed her repeatedly.
Vicki Robinson’s body was later found in a garbage can in the woods near her home. The teens took her car, cash and credit cards and spent the next few days in motels, spending money on tattoos, according to case records. They left town upon hearing that the murder had been discovered. They were arrested after a high-speed chase in Pecos County, Texas.
A jury convicted Valessa Robinson of third-degree murder. She received a 15-year prison sentence and was released in 2013.
Whispel pleaded guilty to second-degree murder and received a 25-year sentence. He was released from prison in 2019.
Only Davis remains incarcerated.