After three trials that ended in setbacks for prosecutors, the Delaware Department of Justice has abandoned its case against the only remaining defendants charged in the 2017 takeover of James T. Vaughn Correctional Center, which left one corrections officer dead and two others seriously injured.

Attorney General Kathy Jennings' office announced Wednesday afternoon that prosecutors had dropped all charges against Lawrence Michaels and Alejandro Rodriguez-Ortiz, the two inmates left to stand trial for the murder of Lt. Stephen Floyd and other crimes related to the violent ordeal.

The decision follows a string of stinging losses for prosecutors, who were plagued by conflicting witness testimony and a lack of hard evidence linking individual inmates to Floyd's death. Of the 16 inmates charged, only Dwayne Staats was convicted of Floyd's murder. One other inmate, Jarreau Ayers was convicted for riot, kidnapping, conspiracy and assault, but was cleared of the murder charges.

In March, the DOJ announced that it would drop charges against six of the last nine defendants in the case, making Michaels, Rodriguez-Ortiz and Roman Shankaras, who had been portrayed by prosecutors of being the “puppet master” behind the takeover, the only defendants with charges still pending. A jury late last month found Shankaras not guilty of murder and all other charges.

The DOJ said in a statement that the case was “one of the hardest” for authorities to investigate and prove. Prosecutors, the agency said, had spent almost two years trying to piece together what happened the day prisoners in JTVCC's C-Building took control of the facility for more than 18 hours, setting fires and flooding hallways.

“Prosecutors and investigators did herculean work in the ensuing years to find those responsible for the riot and its consequences and to present a case they believed could meet their burden of proof in a court of law,” the statement said.

“Nevertheless, three juries have since shown that proving beyond a reasonable doubt who was responsible for Lt. Floyd's death is no longer possible,” it said.

When authorities finally cleared the building, they found Floyd's body handcuffed and face-down in about two inches of water. Two other guards were taken hostage during the siege, but were later released during negotiations with the Delaware State Police. A fourth victim, prison counselor Patricia May was not injured and was freed when police finally retook the building around 5 a.m. Feb. 2.

Lacking physical, video and audio evidence, prosecutors were forced to rely solely on statements of more than 100 inmates, who the DOJ said were both suspects and witnesses. According to the DOJ, the “handful” of inmates who agreed to testify at trial had to be housed apart from the other prisoners because they had risked their own safety to provide their account of the events.

“The trial team appreciates their willingness to try to help bring justice in these cases, and rejects any implication that any witness was pressured to testify,” the statement said.