KNOXVILLE, Tenn. (WVLT) -- Accused killer Vanessa Coleman's back in the trial line-up for the kidnapping, rape, and murder of a young Knox County couple, court officials said Tuesday.

A three-judge panel with the Tennessee Court of Criminal Appeals issued an order last Friday denying Coleman's pre-trial appeal.

"We were disappointed, as you can imagine. We thought we had a good issue. we still think we have a good issue, but it's all up to whose opinion you believe and you go from there," defense attorney Russ Greene said.

Greene said he's deciding whether to appeal the order to the full state Court of Criminal Appeals or the Tennessee Supreme Court.

Greene had argued an immunity agreement prepared by federal prosecutors protected the defendant from prosecution by the Knox County District Attorney General Office.

Coleman is the fourth defendant charged with the January 2007 kidnapping, rape, and murder of Channon Christian and Christopher Newsom.

Separate juries have already convicted accused ringleader Lemaricus Davidson to death and co-defendant Letalvis Cobbins to life in prison without parole for the crimes.

Co-defendant George Thomas' trial began Wednesday morning.

Coleman's attorneys said federal prosecutors had drafted a immunity agreement in exchange for testifying before a federal grand jury, regarding the events leading up to the couple's death.

Coleman "never invoked her Fifth Amendment privilege against self-incrimination before testifying," the order stated.

Her defense attorneys argued the charges arose from a joint investigation by state and federal authorities.

Coleman's defenders said federal authorities acted as "agents" of the DA's office when she was subpoenaed to testify.

Coleman's attorneys said that was enough to trigger the immunity protection, based on a cited legal rule. Therefore, they say, she was protected against prosecution from the state.

The panel of judges disagreed.

"Even if we concluded in a [pre-trial] appeal that the federal authorities were acting as agents of the District Attorney General....there is a strong likelihood that [Coleman] still would not prevail on the argument that she is entitled to immunity from the prosecution," the judges wrote.

The judges also cast doubt on Coleman's success on a post-trial appeal.

"We cannot conclude that the defendant's probability of success on appeal is so great as to justify [this] appeal," the order stated.

Greene told Volunteer TV News he expects Coleman's trial date to be set in early 2010.