The governor of the U.S. state of Rhode Island is set to pardon John Gordon, an Irish immigrant, who was hanged 150 years ago following what is believed to be a tainted murder trial.

Gordon was convicted of killing the brother of a U.S. senator and hanged in 1845. Historians and law professors believe the evidence against the immigrant was circumstantial and the trial was tainted by bigotry against Irish Catholics.

Governor Lincoln Chafee is scheduled to sign the pardon Wednesday, in Rhode Island's Old State House, the site of Gordon's trial.