FAIRBANKS — The leader and two members of a Fairbanks militia group are again facing murder conspiracy charges, this time from federal prosecutors who say the three had a plan as far back as 2009 to kill federal officials.

The charges against Schaeffer Cox and the two others are punishable by life in prison.

A federal grand jury in Anchorage on Friday returned a new indictment with the added murder conspiracy charge against Cox, Coleman Barney of the North Pole area and Lonnie Vernon of Salcha. They pleaded not guilty on Monday before Judge Robert Bryan, brought from Tacoma, Wash., to hear the case.

The three members of Cox’s Peacemaker’s Militia have been in jail on weapons charges since March. They were scheduled to go to trial next month. The new charges caused the trial date to be moved to May 7.

This is not the first time the group has been charged with murder conspiracy. In March, state prosecutors charged the three along with Vernon’s wife, Karen Vernon, and Michael O. Anderson of the Fairbanks area. That case was thrown out last fall when a state judge ruled secret recordings made by two FBI informants without a search warrant were not admissible in state court. However, the judge indicated they likely would be usable in federal court.

In the state case, Cox and the others were accused of developing a plan called “241” to resist any attempt to arrest Cox on a pending arrest warrant, if necessary killing two troopers or court officials for every militia member killed in any ensuing struggle.

Cox argued at the time that the state did not have jurisdiction to arrest him because he considers himself a “sovereign citizen” and not subject to state law.

The federal charges restore part of the state’s case. The charges accuse Cox of planning to kill other government agents as early as fall 2009, well before spring 2010 when FBI has said it began its formal investigation into Cox and sent informant Gerald “JR” Olson to infiltrate his group. The charges say Cox and an “unindicted co-conspirator” began collecting personal information of people associated with the government, including TSA agents, the Border Patrol, federal marshals and Alaska State Troopers.

The indictment says the information was being gathered allegedly to come up with a plan for killing government agents. The same “unindicted co-conspirator” also drew a sketch of the Federal building in Anchorage, according to the indictment.