The state's highest criminal court on Wednesday rejected the latest appeals by death row inmate Rodney Reed, who argued that his conviction for a 1996 Bastrop County murder was based on false scientific evidence.

The unanimous ruling by the Court of Criminal Appeals also rejected Reed's claim that new evidence called into question testimony provided by Jimmy Fennell, the fiancé of murder victim Stacey Stites.

Reed and his lawyers argue that Fennell killed Stites, perhaps after learning about her secret affair with Reed. Reed claimed he and Stites were romantically involved after DNA tests linked Reed to sperm found on her body.

Bryce Benjet, a lawyer for Reed with the Innocence Project of New York, said defense lawyers were exploring additional options for presenting the new evidence to the 5th U.S. Circuit Court of Appeals and the U.S. Supreme Court.

"The Court of Criminal Appeals’ denial of Mr. Reed’s case simply cannot be squared with the compelling and uncontradicted evidence of his innocence," Benjet said. "Although we are still reviewing the opinion, this is by no means the end of the case."

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Wednesday's ruling marked the latest legal setback for Reed, whose team of volunteer lawyers has launched an aggressive campaign to challenge his conviction, including unsuccessful efforts to have crime scene evidence tested for DNA, arguing that the results could prove his innocence.

The Supreme Court rejected Reed's DNA appeal one year ago, and Benjet said Wednesday that Reed intends to file a federal civil rights lawsuit to force testing on Stites' clothing and two pieces of the belt used to strangle her to determine if the killer left skin cells and other DNA-bearing evidence.

Now 51, Reed was 10 days from execution in 2015 when the Court of Criminal Appeals stepped in to order a closer look at his claim that new evidence showed he did not kill Stites — including experts in forensic pathology who determined that Stites had been killed hours before she and Reed could have crossed paths.

FROM 2016: Rodney Reed execution halted by state court

Although that appeal was eventually rejected in 2017, it led to two follow-up appeals that the court addressed Wednesday:

• Defense lawyers argued that Reed's conviction was based on testimony from three scientific experts that is now acknowledged to have been wrong.

The prosecution experts testified that the condition of Reed’s sperm cells — with tails still attached — showed the semen had been deposited no more than 26 hours before the cells were examined, or around the time Stites was believed to have been killed, because intact sperm cells can last no longer inside the body.

The testimony bolstered prosecution arguments that Stites had been raped and killed by Reed as she drove from the Giddings apartment she shared with Fennell to her early-morning job at a Bastrop grocery store.

In recent years, the employers of two of the experts have backed away from the testimony, while the third — Dr. Roberto Bayardo, the former Travis County medical examiner — acknowledged that a 26-hour time limit for intact sperm cells was not “medically or scientifically supported.”

The Court of Criminal Appeals, however, rejected the sperm cell information without examining its merits, ruling it had been available during earlier Reed appeals. State law allows subsequent appeals only if previously unavailable evidence had been discovered, the court said in its unsigned opinion.

• Reed's lawyers also argued that new evidence bolstered claims that Stites was killed by her fiancé, Fennell.

They pointed to a 2016 TV interview given by Curtis Davis, who was good friends with Fennell and Stites, in which Davis recalled Fennell saying 20 years earlier that he had returned home between 10 and 11 p.m. the night before Stites died.

Fennell had told investigators that he returned to the apartment around 8 p.m. and was with Stites until she left for work around 3 a.m.

Reed's lawyers argued that the new timeline, when combined with new opinions from forensic experts that put the time of Stites' death before midnight, made Fennell the only likely suspect.

After a four-day hearing on the matter in October, Visiting Judge Doug Shaver disputed the significance of the evidence, noting that Davis said Fennell never provided a specific time of his return home and that Davis surmised it was after 10 p.m.

In contrast, Shaver said Carol Stites — the mother of Stacey Stites, who lived in the same apartment building as her daughter — credibly testified that Fennel had arrived home "right before dusk," which would have been around 8 p.m.

In Wednesday's ruling, the Court of Criminal Appeals rejected Reed's request for a new trial, citing Shaver's conclusions and "our review of the record."