This Fayetteville Observer article reports on his latest effort in federal district court in Kansas. He claims that he was not subject to trial by court-martial because his active duty had been interrupted following the 1985 offenses:
Hennis resumed his Army career [following an ultimately unsuccessful state prosecution in North Carolina], retiring as a master sergeant in 2004.
Two years later, the Army brought Hennis out of retirement to face a court-martial on the charges after DNA evidence not available at the earlier trials linked him to the murders. . . .
In arguments to various courts, Hennis' lawyers have said that a break in service between his time on death row and his resumption of his Army career should have prevented the Army from bringing charges against him.
Petitions to the Army Court of Criminal Appeals, U.S. Court of Appeals for the Armed Forces, U.S. District Court for North Carolina, 4th U.S. Circuit Court of Appeals and U.S. Supreme Court have made the case that the Army ignored the law by disregarding Hennis' break in service.
The petitions also argue that the federal statute that allows members of the Army Reserve to be recalled to face criminal charges applies only to offenses alleged after March 12, 1987, more than two years after the Eastburn murders.
A separate statute that allows the Army to recall retired service members permits the force to do so only "in the interest of national defense," according to Hennis' lawyers.The background of the case is set forth in this 2012 Fourth Circuit decision unanimously affirming (with minor modification) a district court abstention ruling.