Singer Rihanna tweeted, "One click !!! SIGN this petition if you don't believe the government has to kill an innocent man," and tagged the government of Texas Greg Abbott. Read more States confessed to killing him years ago. The fiancé's lawyer said the request was not credible.
In recent weeks, other witnesses have emerged who have suggested Reed is innocent.
Last week, Reed's attorneys petitioned for clemency as they tried to suspend his execution on November 20.
His lawyers have been fighting for a new trial for years, and the court suspended his execution in 2015 because of new witness testimony and forensic analysis. In the end, the court ruled against Reed.