In 1987 Jerry Lee Evans was convicted of rape and sentenced to life in prison based on eyewitness reports and circumstantial evidence. Today he is expected to become the 20th person in eight years in Dallas County to be exonerated through post-conviction DNA testing.

Like 18 of his fellow exonerates, Evans was convicted based on eyewitness testimony and circumstantial evidence.

At the time of the 1986 rape of an 18-year-old Southern Methodist University student Evans matched the description of the rapist, including having a speech impediment.

However, post-conviction DNA testing has proven Evans was wrongfully convicted. On Tuesday district attorney Craig Watkins said post-conviction tests have proved Jerry Lee Evans is innocent

Last year The Dallas Morning News published a series that showed all but one of the DNA exonerations used faulty eyewitness testimony to convict.

Since it first allowed post-conviction DNA testing in 2001, Dallas County has risen to be the leading jurisdiction in America for the number of exonerations due to DNA testing results.

Forty-seven-year-old Evans, has been behind bars for more than two decades.