A Texas man who spent nearly 20 years on death row has been exonerated - almost 47 years and three trials since he was sentenced for murdering and raping his neighbor.

Kerry Max Cook, now 68, was found guilty of murdering Linda Jo Edwards, 21, back in 1978.

But on Wednesday, the Texas Court of Criminal Appeals declared that he is 'actually innocent,' after evidence was withheld in his first trial in 1978 and some of the expert testimony was later proven to be false.

'This case is riddled with allegations of State misconduct that warrant setting aside Applicant's conviction,' Justice Bert Richardson wrote in the court's opinion.

'And when it comes to solid support for actual innocence, this case contains it all - uncontroverted Brady violations, proof of fake testimony, admissions of perjury and new scientific evidence.' 

Edwards was found brutally murdered and mutilated in her bedroom in an apartment complex in Tyler, Texas in 1977.

Cook lived in the same complex, and police claimed a set of fingerprints on Edwards' sliding patio door matched those of Cook.

The star witness at that first trial in 1978, Edward Scott Jackson, also testified that Cook told him he killed Edwards. 

He was sentenced to death in 1979, and during his time on death row, Cook was stabbed and raped by other inmates, Texas Monthly reports.

But Jackson later recanted his testimony, saying, 'I lied to save myself.'

An expert witness - a sergeant who was deemed a fingerprinting expert - also admitted he was pressured by the District Attorney's office into claiming the fingerprints were fresh, according to the Death Penalty Information Center.

A scientific analysis and expert testimony would later debunk the claim.

It would later also be revealed that during the course of the investigation, police destroyed human hair - which could have contained exculpatory evidence.

Richardson described these actions in his opinion on Wednesday as going 'beyond gross negligence' and reaching 'into the realm of the intentional deception against the tribunal.' 

Cook's conviction was then overturned in 1991, and a second trial one year later ended in a mistrial when the jury was unable to reach a unanimous verdict.

A third trial in 1994 ended with a new conviction and death sentence, but once again, the Texas Court of Criminal Appeals found that Cook's due process was violated, reversed the conviction in 1996 and remanded the case to the trial court.

Cook was freed from prison the following year. 

By 1999, the results of DNA testing on Edwards' underwear came back a negative match for Cook.

It instead matched Edwards' boyfriend at the time, James Mayfield, who was married and was twice her age, Texas Monthly reports.

Mayfield had also lied about his whereabouts on the night of Edwards' murder.

Before a fourth trial in 1999, Cook agreed to a 'no contest' plea deal in which he would be sentenced to 20 years in prison and given time served - but the conviction would stand. 

Still, Cook continued to fight for exoneration and became an outspoken critic of the death penalty, writing a book entitled Chasing Justice. His story would also become the subject of a hit play, The Exonerated.

By August 2016, the trial court recommended Cook be granted relief based on the false testimony, but found that the new evidence did not prove innocence.

Judge Richardson, however, disagreed with the ruling in his opinion on Wednesday,

'The State merely has to prove guilt beyond a reasonable doubt - which the State could never achieve in this case,' he wrote.

'Cook should therefore not have to prove his innocence beyond all doubt.'

'After being incarcerated on death row for almost 20 torturous years, we hold that Cook has met the burden required for actual innocence and relief is hereby granted.' 

Kerry and his attorneys celebrated the news.

'Kerry suffered immensely for nearly 50 years and nothing can give him his life back,' attorney Glenn Garber, of the Exoneration Initiative, told CNN. 

'The decision finally and forcefully clears his name, and at the same time chronicles the state's outrageous and unrelenting misconduct,' he continued.

'It is important for the people of Tyler, Smith County and the world to understand what it was all along - a disturbing witch hunt by state actors.'

The opinion from the appeals court, though, noted it did not hold the current prosecutors 'in any way responsible for the past events in this case.' 

But the good news for Cook came just as he suffered a stroke, with doctors informing him that the arteries were 90 percent blocked.

'They're performing life-threatening surgery,' he told Texas Monthly. 'I hope I come out of it.

'I was praying, "I hope they rule and set me free,"' he continued. 

'Because if I die, at least I want to be able to know that I won.'