The state's decision last week to drop charges against most of the remaining defendants charged with the murder of Lt. Steven Floyd came on the heels of two trials that were plagued by a lack of hard evidence and inconsistent witness testimony, Delaware defense attorneys said.

Prosecutors with the Delaware Department of Justice to date have secured just one guilty verdict in the high-profile murder cases stemming from the 2017 inmate takeover of James T. Vaughn Correctional Center in Smyrna. On March 15, the state announced that it would only proceed with charges against three of the nine inmates still waiting to stand trial in Wilmington for murder, riot and other charges.

The DOJ declined to comment any further on the cases.

In the absence of substantial physical and video evidence, prosecutors have been forced to rely on the accounts of prisoners. Some of that testimony proved to be contradictory, according to defense counsel in the case and other courtroom observers. Those problems, the attorneys said, combined to undermine the state's theory of accomplice liability, which is typically considered a powerful tool for the state in complex criminal prosecutions.

Juries instead have tried to sort through prisoner testimony in order to piece together the individual involvement of each defendant, leading to disappointing results for prosecutors.

“The state's really backed into a corner,” said Michael W. Modica, a Wilmington-based criminal defense attorney.

“It's a defense attorney's dream,” he said.

A linchpin of the state's case, accomplice liability allows a jury to find defendants criminally responsible for a crime committed by another person, so long as they assisted in carrying out an underlying “target” crime. Under the same theory, defendants can also be convicted of any other foreseeable crimes that occurred as a result of the underlying offense.

In the Vaughn trials, the state has admitted that it lacks evidence regarding who actually delivered the fatal blows to Floyd, a veteran corrections officer, during the 18-hour-long siege two years ago. Rather, the state has argued that a contingent of inmates from Vaughn's C-Building had conspired to take over the prison, and thus were liable for all other crimes that resulted from their plan being put into motion.

Two other corrections officers were taken hostage and suffered serious injuries, but were later released during negotiations with the Delaware State Police. A fourth victim, prison counselor Patricia May, was not injured and was eventually freed around 5 a.m. Feb. 2, when authorities stormed the building and finally ended the uprising.

In total, 18 inmates were charged in connection with the ordeal, and 16 had faced felony murder charges in addition to riot, kidnapping, assault and conspiracy.

The first trial ended with Dwayne Staats, who admitted to planning the takeover as a way to protest prison conditions, convicted of first-degree felony murder and murder of a law enforcement officer. His co-defendants, Jarreau Ayers and Deric Forney, were both found not guilty of the most serious murder charges. Ayers was convicted of the four lesser charges. Forney, who denied any involvement in the uprising, was acquitted on all charges.

Another jury returned no guilty verdicts against any of the four inmates in the second set of defendants tried earlier this year.

Attorneys have described the prosecution so far as hampered by a slew of evidentiary problems, which included a lack of surveillance footage from the prison and spotty testing of improvised shanks found at the scene. During the takeover, the prison's sprinkler system was deployed, contaminating some of the key evidence the state did have.

Prosecutors have been forced to lean heavily on the testimony of prisoners who were in C-Building at the time of the takeover. Those accounts, however, have often failed to line up, and the witnesses, themselves convicted felons, have been particularly susceptible to impeachment on cross-examination.

Juries, likewise, have been left to question the credibility of the prisoners, as well as the motivations behind their testimony.

“I don't think a jury can make heads or tails of who was involved and who wasn't involved,” said attorney Thomas A. Pedersen, who represented defendant John Bramble at the second trial.

“Each individual witness has told so many different stories” that “you can't come close” to proving the case beyond a reasonable doubt, Pedersen said in an interview.

The difficulties inherent had also led some to question the viability of the state's case going forward. Earlier this month, attorneys said that prosecutors would need to adjust their strategy, possibly eliminating witnesses and resolving some of the cases before trial.

“The defense is now armed with testimony from two trials, and they'll be able to confront witnesses with their own inconsistencies from prior testimony,” said Modica, who was not involved in any of the cases.

The DOJ said last week that its top priority was “obtaining a measure of justice” for the victims of the uprising, but acknowledged that “prosecutors have an obligation only to prosecute criminal cases where they believe there is a reasonable likelihood of a conviction at trial based on the evidence.”

As such, the agency said that it had informed the court that it would only proceed with charges against Roman Shankaras, Lawrence Michaels and Alejandro Rodriguez-Ortiz.

“Prosecutors in the Vaughn trials—who are among the department's most experienced and who have done a remarkable job in an exceedingly difficult case—have evaluated the evidence against the remaining defendants in light of the testimony in the first two trials and the results of those trials,” the DOJ said in a statement.

“This was discussed with the victims in the case and they were informed of the decision. Due to the still-pending criminal cases, DOJ will make no additional statement on this decision.”

Brendan O'Neill, chief defender for the Office of Defense Services, applauded the efforts of the private attorneys who have represented the defendants as conflict counsel.

“I commend the defense lawyers on their efforts to date,” he said. “Their good efforts exposed the difficulties the state faces in attempting to prove a case beyond a reasonable doubt and relying primarily on inmate testimony. That's especially difficult when there is little or no forensic evidence and no video evidence to corroborate the testimony of the inmate witnesses.”

Shankaras, who was severed from the first trial, is set to stand trial next month. Michaels and Rodriguez-Ortiz are slated to be tried in October.