JACKSON COUNTY, Mo. — Jackson County’s prosecuting attorney says they’re facing a not only a tragic outcome, but a rare one, in one of their murder cases.

Jean Peters Baker said double jeopardy allowed a murder suspect to walk free.

In May 2017, Independence police said 57-year-old Holly Barnett was beaten to death in her own home. Courtney Hackney was arrested, charged and then went to trial that resulted in a mistrial.

However, there will be no re-trial, and Barnett’s family is demanding answers.

Peters Baker said they planned to retry the case, but because of a procedural rule, they were shocked to find out they would have to let Hackney go.

Barnett’s family said they want to see if anything can be done.

“I can’t tell you what happened,” Barnett’s cousin, Bettie Tye said. “What did happened? That’s what we’d like to know.”

Independence police said that day in May, Barnett was beaten to death with a bat while she was sitting in her recliner. Barnett’s family said she faced two other instances in her life that resulted in traumatic brain injury, which left her worse off each time.

A resident of the home told police that Hackney had let her inside the home, telling her that Barnett was sleeping. The resident attempted to run out of the house, but Hackney tried to drag her back in. She was able to get free and call police.

Police later found Hackney in the area of Woodlawn Cemetery. Hackney reportedly told police Barnett was her aunt and said the bat was hers.

Witnesses told police they often saw Hackney carrying the bat.

Peters Baker said she believes Hackney killed Barnett, and they had evidence to prove it.

“I heard it on the news, and I called to find out what was going on, and I found out it was Holly,” Barnett’s cousin, Jane Gaughran, said.

Her family said Barnett helped anyone she could, including Hackney, by letting her and others live in her home.

Peters Baker said that was her downfall.

The case went to trial at the end of last year, but resulted in a mistrial. Peters Baker said when the went to try it again, they faced a problem they didn’t expect.

“That witness was unavailable for this trial setting forcing us to not be able to proceed with the case,” Peters Baker said. “The case was then dismissed, and then immediately refiled. Upon that dismissal this procedural rule of double jeopardy went into play.”

Double jeopardy: It’s traditionally known as a person being tried twice for the same crime. Peters Baker said there’s a procedural rule where if a case has already gone to trial you cannot dismiss the case and then refile after that dismissal.

“To know that we’re barred in a way that’s such a rare circumstance that would lead to this outcome — it angers me,” Peters Baker said.

Hackney was cleared of all charges and released Monday.

“Where is justice?” Gaughran said. “Is this why you got into this to see if you could be the best person to find the loophole, or do you really want justice? Justice will come. If it doesn’t come on this earth it will come on the next.”

“It’s a hard pill to swallow,” Peters Baker said. “The law is the law. We’ll follow it whether or not we agree with the law or don’t, like it or don’t. When you’re a prosecutor those are not your decisions to make. We all took an oath to uphold it. That’s what we did here, but I don’t like the outcome.”

The prosecuting attorney said there is a possibility to retry the case, but the law would have to change. Traditionally it’s in place to keep lawyers from abusing the system, but she said, in this case, it was an unfortunate technicality.

FOX4 reached out to Hackney’s attorney, but have not received a response.