NASHVILLE, Tenn. (AP) — Friends and family of Tennessee death row inmate Gary Sutton held a news conference outside the state Capitol on Friday to publicize Sutton’s effort to pursue his innocence claims and have his public defender removed from his case after they said she did not meet with him for 12 years.

Sutton’s supporters include Carolyn Miller, who was his girlfriend in 1992 when Tommy Griffin and Griffin’s sister Connie Branam were murdered in Blount County. Miller said in an interview that she knows Sutton is innocent in the siblings’ deaths because he was with her the weekend they were killed.

Gary Wayne Sutton. Photo: Tennessee Dept. of Correction

Sutton, 58, has been on death row since 1996. His co-defendant, James Dellinger, died while imprisoned on death row earlier this year of what authorities said were natural causes.

Several years ago, fearing Sutton’s execution was near, Miller and others hired a private investigator to look into the crimes he was convicted of, Miller said.

Investigator Heather Cohen, who was also at the Capitol on Friday, told reporters she uncovered “indisputable facts of exculpatory evidence, witness tampering and constitutional violations.” Cohen said she even found evidence that another person committed the murders. She also made a public offer to show that evidence to Gov. Bill Lee, who has the power to grant clemency to Sutton.

Cohen and Miller said Sutton’s federal public defender, Susanne Bales, has been hostile to their efforts, and Sutton’s brother Jimmy Sutton said in an interview that the attorney repeatedly refused to provide them with information about the case. They said Gary Sutton is petitioning the federal district court in Knoxville to remove Bales from his case. However, Sutton’s petition had not yet been filed with the court as of Friday afternoon.

Asked through a spokesperson about Sutton’s claim that Bales had not met with him for 12 years, Bales said in an email that ethics rules do not allow her to comment.

Bales and the rest of Sutton’s legal team issued a statement on Friday, saying: “We join many Tennesseans in being gravely concerned about Gary’s fate and are working within the bounds of our legal system to ensure that Gary is not executed for a case that is riddled with problems. The scientific evidence linking Gary to the case is from disgraced state medical examiner Dr. Charles Harlan who was later stripped of his license. Gary is also intellectually disabled, and that claim is currently pending in state court. Gary has always maintained his innocence, and we will continue to work hard to fight for him.”