The daughter of a Tennessee man executed in 2006 for a woman's rape and murder filed a petition Tuesday seeking DNA testing of crime scene evidence that she hopes will prove her father's innocence.

Sedley Alley was convicted of the 1985 murder of 19-year-old Marine Lance Cpl. Suzanne Collins in Millington. She had been out jogging when she was kidnapped, beaten, raped and mutilated. Alley confessed to the crime, but later said the confession was coerced.

Barry Scheck, co-founder of The Innocence Project, helped argue for DNA testing in Alley's case before his execution, but that request was denied. The Tennessee Supreme Court later found the earlier ruling misapplied Tennessee's Post-Conviction DNA Analysis Act, but it was too late for Alley.

Scheck, who now represents Alley's daughter April Alley, said the renewed call to test DNA evidence comes after an investigator on a different homicide case contacted The Innocence Project about a possible alternative suspect in Collins' slaying.

Evidence Scheck wants tested includes a pair of men's underwear recovered at the scene/ DNA testing of evidence was in early stages in the 1980s, and no DNA evidence has ever been tested in Sedley Alley's case.

Scheck spoke at a news conference Wednesday in Nashville. April Alley also spoke briefly, breaking down in tears.

She and her brother had witnessed her father's lethal injection in 2006. They had their hands up against the glass as he spoke his last words, telling them he loved them and to "stay strong."

"Watching my father die was so painful," she said. "I'm hoping I can get the answer, one way or another, that I want."

April Alley's attorneys filed the new petition for DNA analysis with the criminal court in Memphis on Tuesday. That is the court where Alley was convicted in 1987.

District Attorney Amy Weirich said by email that the case and conviction were repeatedly scrutinized by state and federal courts over 21 years and that the state Supreme Court found in 1989 that Sedley Alley's guilt was established with "absolute certainty."

Still, she wrote, "The efforts to make the defendant a victim continue to this day. What we are focused on right now is contacting the family of Suzanne Collins and reviewing the petition to determine next steps."

Scheck said his New York-based nonprofit, which seeks to exonerate people wrongly convicted of crimes, also has tried to reach out to Collins' family about the request.

"This is, I'm sure, extremely difficult for them," he said.

Kelley Henry is an assistant federal public defender in Nashville who worked on Sedley Alley's case after his first federal appeals.

Speaking at the news conference, Henry said she reviewed the case exhaustively and found earlier attorneys failed Alley by assuming he was guilty and trying to prove insanity.

"As a former trial attorney, when I started looking at the evidence, I immediately recognized that this was a case of innocence," Henry said.

She said she found the confession didn't match crime scene evidence.

According to Henry, the coroner's report had been suppressed, but it put the time of death at a time when Alley was known to be at home after having contact with police over a domestic incident. She also said Alley's appearance and that of his car didn't match witness descriptions — tire treads didn't match those at the scene nor did his footprints.

Alley initially denied he committed the crime but signed a confession after twelve hours of questioning, according to court documents. He later told his attorneys he had been drinking heavily and did not remember the crime.

Alley's confession said he had hit Collins with his car, but the blood on his car was determined to likely belong to a bird, Scheck said. And Collins hadn't been run over. Alley also told police he was trying to start the car with a screwdriver when he accidentally stabbed Collins in the head after she startled him. But according to Scheck, the coroner's report didn't show a wound like he described.

Separately, April Alley's attorneys have written Gov. Bill Lee requesting he use his executive power to order testing. A spokeswoman for Lee said by email that he has no comment on the application.

Asked what would happen if the DNA testing showed Sedley Alley did commit the murder, Scheck said, "We're not afraid to find the truth. All we've ever asked for is the truth."