2 serving life sentences accused in more slayings in suspected rape and murder spree in Florida

Two men have been charged in two Tampa Bay-area cold-case murders based on DNA evidence that exonerated a death-row inmate.

Their indictments in the decades-old cases were announced Thursday.

Robert Duboise was wrongfully convicted of the capital murder of Barbara Grams, a 19-year-old who was raped and found beaten to death behind a dental office in Tampa in 1983.

He was released in August 2020 after DNA evidence was tested in the case, according to The Innocence Project, which represented him.

Barbara Grams. (Florida State Attorney’s Office, 13th District)
Barbara Grams. (Florida State Attorney’s Office, 13th District)

A conviction review unit continued to investigate, and the DNA evidence identified Amos Robinson and Abraham Scott as suspects, according to the Hillsborough State Attorney’s Office. The investigation also tied Scott and Robinson to another unsolved rape and murder from the same year, the prosecutor's office said.

Linda Lanson, a freelance photographer, was fatally shot in the head and dumped in the bushes by a highway in July 1983.

“These men are serial murderers and rapists, and although they’re already serving life sentences, their crimes against Barbara Grams and Linda Lanson cannot — and will not — go unpunished,” Hillsborough State Attorney Andrew Warren said.

Warren provided the update in the cases Thursday, despite being suspended from office by Florida Gov. Ron DeSantis earlier in the day. The governor said Warren’s refusal to enforce restrictions on abortion and gender-affirming therapy for minors showed Warren was neglecting his duty.

Warren said the two men conducted a “sinister spree of rape and murder” in the Tampa Bay area in 1983.

Robinson and Scott are already serving life sentences for the murder of a man who was kidnapped, beaten and run over with his own car in October 1983.

On Thursday, a grand jury indicted them in the rapes and murders of Grams and Lanson. Robinson was previously charged with a murder in 1991, but the case never went to trial due to a lack of evidence, Warren said.

It's unclear if the two men have retained attorneys in the rapes and murders of Lanson and Grams.

Lanson's niece, Linda Sheffield, thanked Warren and law enforcement for finding justice for her aunt, who she called a beautiful artist and photographer who was a "strong, determined, warm and wonderful woman."

"There are no words to describe what it is to go through 39 years of grief and not knowing what had happened," Sheffield said. "You know, I think at some point you stop and you forget about the criminals and you start to realize the void ... that is there for someone who helped you for so long."

Lanson's daughter declined to speak to reporters Thursday, but Warren read a statement on her behalf. She expressed gratitude to everyone involved for their diligence in working on her mother's cold case.

"For me, the loss of my beautiful mother will remain a waking nightmare," the statement said. "But I thank them for at least bringing me some closure."