Editor's note: This story has been updated throughout.

Two sets of attorneys who believe their client doesn't belong on death row are fighting not only the state of Texas but also each other as his case arrives at the U.S. Supreme Court.

Robert Leslie Roberson III was sentenced to death for killing his two-year-old daughter in 2002. Because the jury didn't hear from a defense expert who thought Roberson might suffer from mental lapses caused by a brain injury, his attorneys have since asked state and federal courts to throw out his conviction.

In May, the U.S. 5th Circuit Court of Appeals ruled that Roberson has grounds for further appeal on the issue. But since that ruling, a rift has developed between Roberson and his appellate attorneys, Wes Volberding and Seth Kretzer. 

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Roberson decided earlier this year that he wanted new lawyers so he can pursue the argument that Volberding and Kretzer have mishandled his appeals.

A court wouldn't let Roberson sack his old attorneys, though, so he reached out and acquired three pro-bono ones from the nonprofit Texas Defender Service, effectively creating two legal teams fighting for the same end by different means.

The Supreme Court on Friday will consider a petition from Texas Defender Service attorneys, who argue that another attorney should be added to the Volberding-Kretzer team to help with Roberson's appeals process. Volberding and Kretzer argue in a parallel petition filed Tuesday that Roberson should receive a new trial because his expert wasn't allowed to testify.

“It's actually pretty simple,” said Lee Kovarsky, Roberson’s lead attorney from Texas Defender Service. “If the client wants them to do something that they're not doing, and we're doing it, we're actually acting on behalf of the client and they're opposing their client.”

After conviction, an inmate's appeals follow well-worn tracks through state and federal courts. After the underlying conduct of the trial is affirmed, death row inmates typically pursue habeas appeals, in which they say their conviction should be reversed based on claims that weren't used at trial.

That's where Roberson is now, arguing that a defense expert would have testified that he has a disorder that interferes with his ability to make rational decisions and intentionally or knowingly carry out an act.

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During federal habeas proceedings, an appeals lawyer can also raise a Sixth Amendment claim, arguing that their client had ineffective assistance from the attorney who represented them in state proceedings. In Roberson’s case, Volberding was Roberson’s attorney during state post-conviction proceedings and now represents him in federal proceedings.

Because Volberding represented Roberson in both sets of habeas proceedings, he can't check his own work, say attorneys with Texas Defender Service. They also argue that Volberding’s co-counsel, Kretzer, can't get the job done either because the two have worked together on past cases and have a conflict of interest.

Volberding disagreed.

“There is no conflict,” he said. “We're not law partners. We don't share expenses. We have separate offices. We live and work in separate cities. We've teamed up on several of these cases because we each contribute something different, just like doctors and lawyers team up ad hoc on all kinds of cases. There's nothing unusual.”

Kretzer echoed Volberding.

“I fight for every one of my clients as hard as possible,” he said.

Roberson’s relief would be having another attorney investigate Volberding’s work, said Jordan Steiker, director of the University of Texas School of Law’s Capital Punishment Center.

“I think that their judgment was probably undermined by the conflict that they had with one of the attorneys, Volberding having represented him during state habeas proceedings,” he said.

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It’s unclear, though, Kovarsky said, if Volberding made any errors in past proceedings.

“Nobody really knows because the whole point of the claim is that it hasn't been investigated,” he said. “Ordinarily, the post-conviction lawyer would have investigated it. And so you can’t say anything about the merit of the claim because nobody's investigated it.”

Kovarsky and TDS are academics testing out a theory, trying "to game the system" and force an execution delay, Volberding said.

“The three people on the other side of this are academics,” he said. “They are living in a world that is theoretical, and they are spinning theories hoping something might stick. And these theories are unrealistic.”

Kovarsky rejected the claim, saying that although he is a law professor — the only one of the attorneys working with Roberson — Texas Defender Service is a high-profile capital litigation team where he also is the director of the post-conviction group.

“TDS did not select Mr. Roberson as a test case for some prefabricated theory,” Kovarsky said. “Frankly, we never contemplated that lawyers subject to a conflict of interest would not only refuse to pursue a claim that might save a client's life, but that — in refusing to step aside for an unconflicted lawyer — they would actively undermine their own client's case.”

Roberson’s case is in unique position. Both legal teams see a chance for victory if they don’t get in each other’s way.

“This is his last chance to have consideration of the Sixth Amendment claim,” Kovarsky said. “The Sixth Amendment claim is extinguished forever unless we win. And the Sixth Amendment claim can save his life.”

If the court rejects Roberson’s petition from Kovarsky, it could adversely affect Roberson’s other petition from his appointed attorneys, Kretzer said. However, Volberding said in an October letter to the Supreme Court clerk that it was his understanding that would not be an issue.

Kretzer said he was surprised Kovarsky only raised the conflict claim in his petition.

“You only get one chance to raise merit issues,” he said.

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