An Irish-American woman has pleaded guilty to the horrific murder of a former Arkansas senator in June 2019 after initially entering a not-guilty plea. 

Rebecca Lynn O'Donnell, 49, admitted to the capital murder of state Senator Linda Collins in June last year and then hiding the body from authorities. 

"I went to Linda's house, and I intentionally killed her and then hid the body," O'Donnell told Judge John Fogleman in Pocahontas, Arkansas, on Thursday. 

O'Donnell was sentenced to 54 years in prison after pleading guilty after prosecutors initially sought the death penalty in the case.

Her guilty plea brings a shocking tale of murder to an end, which also involved a murder-for-hire plot while O'Donnell was detained during her trial. 

But it was the nature of the gruesome nature of the murder of the former politician that really grabbed attention. 

Collins's body was reportedly so badly mutilated that investigators were unable to identify her, even though she was discovered outside her home. 

Butch Smith, Collins's son, found his mother's body on June 4, 2019. 

"She was lying face down wrapped in one of my old comforters and shoved under a tarp in her driveway. I will never not be able to see that picture burned into my brain," he said in a statement. 

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O'Donnell was Collins's close friend and served as a campaign aide in her unsuccessful reelection campaign in 2018. She also worked in Collins's business and served as a witness in Collins's divorce with her ex-husband Paul Smith. 

Arkansas prosecutors have not explained a motive for why O'Donnell killed Collins, other than saying that the crime was committed for financial reasons. 

Butch Smith said that he believed that O'Donnell was stealing money from his mother. When Collins found out and confronted her, O'Donnell stabbed her to death, Smith said. 

Arkansas police arrested O'Donnell around two weeks after Collins's body was discovered and she was detained in Jackson County Jail for a short period thereafter. 

There, she allegedly tried to recruit several inmates in a murder-for-hire plot to kill Paul Smith, Collins's ex-husband, and frame him with the murder. 

She pleaded no contest to the murder solicitation charges put to her in relation to the Jackson County Jail case and received 14 years in prison.

In total, O'Donnell will serve 40 years in prison for capital murder, 14 years for solicitation, and three years for abuse of a corpse. 

She is eligible for parole under her plea deal. 

Collins's family released a statement following O'Donnell's plea, arguing that they had found swift justice in the case. 

Today our family has found swift justice by way of a plea deal,. We know that there will be some that will not be satisfied with that outcome today. And we realize that whatever punishment [O'Donnell] receives it will never be enough," the statement reads. 

"Today we find some shred of peace that Rebecca O'Donnell will be put away in prison for a very long time unable to hurt anyone else."

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