CHARLESTON (AP) — Two West Virginia residents facing the federal death penalty merit a new trial because the jury that convicted them included someone under federal scrutiny himself, a U.S. District Court judge has ruled.

Prosecutors have yet to decide whether to appeal Monday’s order setting aside the convictions of George ‘‘Porgy’’ Lecco and Valerie Suzette Friend for the 2005 murder of a drug informant.

‘‘Whether or not we appeal, the case will go forward,’’ U.S. Attorney Charles Miller said. ‘‘We will continue with the prosecution.’’

Lecco, 59, and Friend, 46, were found guilty nearly two years ago on federal charges that they targeted Carla Gail Collins to protect a cocaine ring operating from a Mingo County drive-thru pizza parlor. The 33-year-old single mother had been aiding a drug task force before her body was found in a shallow grave in June 2005. She had been beaten and shot.

The jury that convicted the defendants and recommended the death penalty included William Griffith.

Monday’s order said that when he was selected for the trial, Griffith failed to disclose a criminal record that included convictions for drug offenses, and a pending investigation for child pornography.

While either revelation would have knocked Griffith off the jury, U.S. District Judge John T. Copenhaver Jr. focuses on the latter in much of his 69-page ruling.

The FBI had found the pornography on a computer seized from Griffith’s residence in 2002.

He later failed a lie detector test, and was told by letter in 2003 that he was the target of a federal grand jury.

Given that situation, ‘‘it is difficult to imagine one guilty or innocent of such a charge having the ability to set aside the natural fear and turmoil confronted when facing a potential public accusation of misconduct so serious,’’ Copenhaver wrote.

‘‘He might misguidedly think he could please the sovereign concerning the ongoing investigation of him if a prosecution verdict was returned,’’ the judge’s order said. ‘‘He might think he would have increased leverage in avoiding prosecution once the prosecutor made the link between the ongoing investigation and his jury service.’’

The ruling noted that the FBI and federal prosecutors had let the pornography case idle for years and then closed it in May 2007 — apparently unaware that Griffith had just helped return guilty verdicts against Lecco and Friend at trial.

An FBI agent was trying to return the seized computer when he learned that Griffith was a federal juror, during the sentencing recommendation phase.

While lawyers for Lecco and Friend did not at first object to keeping Griffith on the jury, they sought a new trial after the jury recommended the death penalty.

Copenhaver cited conflicting statements as to whether Griffith had been told by the agent that he was no longer under investigation. ‘‘The actual state of affairs is immaterial in the context of a bias determination,’’ the judge concluded.

A lawyer for Friend said Griffith never should have been allowed on the jury.

‘‘We’re pleased and relieved,’’ said the lawyer, Gary Collias. ‘‘It seems to be a well-written, well-reasoned opinion.’’

A lawyer for Griffith did not immediately respond to comment Tuesday. Lecco and Friend have been jailed without bail since their 2005 arrests.

The pair was convicted on a total of 13 counts, which alleged that Friend killed Collins to silence her on orders from Lecco.

Authorities said Lecco promised Friend cocaine and supplied her with a pistol. Two of the charges carried the death penalty.

West Virginia abolished that punishment for state crimes in 1965, but it remains an option in federal cases. Although the jury recommended death, formal sentencing in the case had been on hold.