David Frediani

David Frediani - AP Photo
In 2000, David Frediani was convicted of the murder of Helena Greenwood. A key piece of evidence: Frediani's DNA was found in skin particles underneath Greenwood's fingernails. Ironically, at the time of her death in 1984, Greenwood, a biochemist, was working to find new uses for DNA technology. She was strangled to death in her San Diego home in 1985. Authorities had suspected Frediani of the crime, but had not had enough evidence to convict him.

Frank Lee Smith

Frank Lee Smith - AP Photo
In what is thought to be the first case in which posthumous DNA testing proved a man's innocence, Frank Lee Smith was cleared of the rape and murder of an 8-year-old Florida girl. Smith died of cancer on Jan. 30, 2000. Eleven months later he was cleared of the charges. He had served 14 years on death row for the 1985 murder of Shandra Whitehead. Smith's DNA was found not to match evidence found on the body of the murdered girl.

Shortly after Smith's exoneration, Florida Governor Jeb Bush said that he advocated DNA testing on other condemned Florida inmates.

Ronald Cotton

Ronald Cotton - AP Photo
In 1985, Jennifer Thompson, a college student from North Carolina, sat on the witness stand and testified confidently that Ronald Cotton was the man who raped her. Based on Thompson's testimony, the jury convicted Cotton. He was sentenced him to life in prison.

After spending 11 years in jail, Cotton was exonerated through DNA evidence taken from the crime scene. Thompson's guilt over putting an innocent man behind bars led her to seek out Cotton. After an emotional first meeting, the two say they have developed a friendship.

Earl Washington Jr.

Earl Washington Jr. - AP Photo
In 1982, Earl Washington Jr., a mentally retarded man, was sentenced to death for the rape and slaying of Rebecca Lynn Williams in Culpepper, Va.

Washington, now 40, came within nine days of being executed in 1985, but was granted a stay. In 1993, DNA testing cast serious doubt on his guilt. His sentence was commuted to life in prison. Another, more sophisticated test was done last year, and cleared Washington of the crime. He received a Governor's pardon in October of 2000. He is now free.