“The intent with which an act is done is an operation of the mind and, therefore, is not always capable of direct and positive proof. It may be established by circumstantial evidence like any other fact in a case.”

That language, from the Florida Supreme Court guidelines for jury instructions, was the last thing prosecutors and defense attorneys working the first-degree murder case of accused killer Michael David Jones argued about Monday afternoon before Judge Dan Vaughn recessed his courtroom for the day.

The language is not in the standard criminal jury instructions, so the matter was up for debate.

Assistant Public Defender Stanley Glenn asserted that those words should not be included in the instructions Vaughn would give jurors on Tuesday when sending them out to deliberate Jones’ guilt or innocence.

But Chief Assistant State Attorney Tom Bakkedahl urged Vaughn to instruct the jury “that circumstantial evidence is good evidence,” in Bakkedahl’s words, because the State of Florida’s case relied heavily on jurors filling in the gaps when it came to the death of 26-year-old Diana Duve.

By the conclusion of the six-day trial, jurors knew an awful lot about Jones and Duve, their friends and the soap opera of their turbulent four-month relationship.

Video evidence, witness testimony and a credit card receipt from the wee hours of June 20, 2014, told jurors what Duve and Jones did, who they were out drinking with, and that they left a Vero Beach bar together after two hours of what appeared to be the rekindling of a tumultuous on-again, off-again romance.

Those who had previously never sat through a criminal trial were likely amazed – perhaps even appalled – at the level of detail, down to petty minutiae, that attorneys ask about and witnesses talk about on the stand.

In this tragic novella of a case, there was a nauseating amount of detail – from the recipe for the shots of liquor the couple drank, to the fact they played the jukebox just hours before police say Jones brutally murdered Duve, to the reading of text messages about Jones and his buddy playing video games and discussing sports.

It was easy to get lost in the story, as jurors returned each morning in hopes of getting to the bottom of what happened to the young nurse who was never seen alive again after leaving What-A-Tavern with Jones.
Fast-forward a chapter and jurors heard even more witness testimony – and saw volumes of evidence – about what Jones did, where he went, whom he called and sent text messages to after Duve was the subject of a frantic missing persons case opened by the Vero Beach Police Department.

That investigation over the next few days, conducted by law enforcement agencies in three counties, involved numerous search warrants, interviews, cell phone location “pings” and old-fashioned shoe-leather police work.

By the end of the trial, it was safe to say the prosecution had proven that Jones lied – a lot. It was also safe to say they proved he destroyed evidence, obstructed justice, transported Duve’s body and holed up in a Hampton Inn in Fort Pierce to avoid being found by police or Duve’s increasingly worried and desperate parents, grandparents and friends.

But he was not charged with those things, so he couldn’t be found guilty of them.

Presenting evidence of Jones’ acts, conflicting statements and deceptions as part of the case went to establishing premeditation – that invisible intent that is an “operation of the mind.”

After retiring briefly to his chambers Monday to conduct some legal research and consider the request, and the defense’s objection, Vaughn ruled that the jury would, as Bakkedahl requested, hear the language on circumstantial evidence and intent, because he said it was “a correct statement of the law.”

It was the jury’s job to take all the substantial evidence presented about what happened before Jones and Duve left the bar at 1:13 a.m. on June 20, 2014, and analyze that in conjunction with what happened after Jones surfaced later that day and allegedly began to cover his tracks.

The chapter in between – the one involving Duve taking her last breath, and Jones allegedly driving away in Duve’s car with her near-naked body in the trunk – was where jurors needed to rely squarely upon circumstantial evidence.

How did she die? When did she die? Where exactly did she die? Was she held against her will? How much did she suffer? How long did she struggle and fight back against her assailant?

Forensic evidence presented by a crime scene specialist, a lab technician and no less than three medical examiners attempted to answer most of these questions. The problem was that the medical experts disagreed on some important points.

Three experts with more than a century of combined experience came to different conclusions looking at the same physical evidence.

The defense’s medical expert opined that Duve died from repeated blows to the head, which rendered her unconscious. Then, he thought, she was placed in the trunk of her Nissan Altima very much alive, but died because her body was positioned in such a way that she could not breathe if she did regain consciousness.

The state’s two medical examiners from the 18th Circuit in Brevard plus the 19th Circuit, which includes Indian River County, both said Duve died of manual strangulation. All three gave convincing testimony to support their findings.

Anyone who has tried to decide on a course of medical treatment based upon conflicting doctors’ diagnoses and recommendations could relate to what the Jones jury faced this week.

This confusing morass, delineated by roughly 200 pieces of evidence and dozens of hours of witness testimony, was what 12 jurors were tasked with sorting out.

A jury of Jones’ peers, most without any particular relevant medical, legal or technical expertise, had to reach a consensus on the three elements of the charged crime of first-degree murder – that Duve died, that Jones killed her and that he meant to do it, with intent and forethought.

Anything less would not be premeditated, first-degree murder. Conviction for any lesser crime, such as second-degree murder, would save Jones from Florida’s death row and an eventual end by lethal injection.