Editor's note: Innocent people were locked up, while evidence that could have cleared them was hidden. CNN's Drew Griffin goes inside a justice system where the handling of more than 200 cases is being called "Rogue Justice." An all-new "CNN Presents," Sunday night at 8 ET.
RALEIGH, North Carolina (CNN) -- On September 25, 1991, Greg Taylor was looking to get high. Driving though the streets of downtown Raleigh, he picked up an acquaintance, Johnny Beck, who helped him score the drugs. What happened next would cost Taylor 17 years of his life.
The two men drove to a field off of a remote cul-de-sac to get high. While smoking, "the urge kind of hit me, you know, to -- to spin around in the mud a little bit on the way out," Taylor said recently, "I basically went across the path and might have made it 10 feet before I bottomed out in a ditch."
With the car stuck in mud, Taylor and Beck walked toward the main road when something caught their attention. It was the body of Jacquetta Thomas, a local prostitute who had been brutally beaten and murdered.
The men were afraid to report the crime. "We had drugs on our person. I was driving without a license, had been consuming alcohol, and so there's a litany of reasons that I would not want to talk to police in general," Taylor said.
The next day, when Taylor and his then-wife, Becky, went to pick up his car, police had already taped off the crime scene. Taylor volunteered to tell the police what he knew. "[It] just still never occurred to him that they might be looking at him," Becky said.
Taylor voluntarily went to the police station for questioning, gave police the clothing he wore the night before and offered to take a lie-detector test. That afternoon, he and Beck were arrested for the murder of Thomas.
Police pressured Taylor to implicate Beck, but Taylor consistently maintained they were both innocent.
Taylor and his family believed the trial would vindicate him. His attorney told Becky it was "the weakest case he had ever seen in his entire career. He was really confident that they could get it dismissed. And so he wasn't gonna present any evidence."
But the prosecutor presented overwhelming evidence, including damning lab results indicating there were "chemical indications for the presence of blood" on Taylor's truck. He was convicted, and sentenced to life in prison.
"When you walk in that courtroom, you still have a belief that the truth will prevail," Taylor said, "but after about three to four days of listening to the prosecutor's case, realizing that the truth is not even being heard, you start to question that. When that verdict came down, it was definitely a shock."
Charges against Beck were dismissed in August 1993, because prosecutors said they didn't have enough evidence to charge him. A month earlier, Wake County Assistant District Attorney Tom Ford wrote Taylor in prison, saying if Taylor testified against Beck, the governor might be persuaded to reduce his sentence. One again, Taylor refused, saying they were both innocent.
For 17 years, Taylor tried to overturn his conviction, going all the way to the U.S. Supreme Court. He requested DNA testing, which was denied. Then, in 2007, attorney Chris Mumma from the North Carolina Center on Actual Innocence took his case, and referred it to the newly formed North Carolina Innocence Inquiry Commission.
The commission -- made up of law enforcement officials, attorneys and victims' advocates -- is the only one of its kind in the country and is empowered to investigate cases where there is evidence of wrongful convictions.
"They had subpoena power; they could get access to all the prosecution's records, all the police records, everything that the defense never had access to. ... They could order DNA testing that Greg was denied previously," Mumma said, "And that commission voted unanimously that there was sufficient evidence of innocence in Greg's case that it did merit judicial review."
The evidence they reviewed included an unreliable witness, an inaccurate jailhouse snitch and an improperly trained forensics dog. But there was one more revelation to come.
What the three-judge panel learned shook the North Carolina justice system. In dramatic testimony, a lab analyst revealed that the jury in Taylor's 1993 trial never heard about a second blood test done by the State Bureau of Investigation (SBI) crime lab. That second, more definitive test failed to confirm that the substance found on his truck was blood.
The results of that test, which could have altered the verdict, were buried in the case files for 17 years. That new evidence, along with a host of other problems at his first trial, led the panel to declare Greg was innocent.
As shocking as the buried evidence was a statement made by the SBI analyst, Duane Deaver, on the stand. When asked why he didn't report the key test, Deaver said he was just complying with the lab's accepted practices of the time. (Since then, Deaver has been fired by the SBI, his lawyer says.)
An audit commissioned by the North Carolina attorney general in August 2010 found more than 200 cases similar to Taylor's from 1986 until 2003 in which lab results for blood tests were withheld.
"There were over 230 cases where reports were not complete. Or reports didn't actually correspond to the laboratory notes, or information was not presented in the report that was in the laboratory notes as to the results of the test," said Chris Swecker, a former FBI assistant director who was hired to do the audit, "What we saw was ... just not right."
Attorney General Roy Cooper, whose office is responsible for the SBI, called the report troubling. "It describes a practice that should have been unacceptable then and is unacceptable now."
He has since called for changes, including a new SBI director, higher standards and new certification for SBI scientists. And from now on, all lab reports must be posted online for prosecutors to see, and for defendants to obtain through discovery.