The U.S. soldier, in a deal that spared him the death penalty, pleaded guilty last month to killing two medical staff officers and three soldiers at Camp Liberty in Baghdad in a 2009 shooting that the military has said may have been triggered by combat stress.
Russell faced an abbreviated court-martial at Joint Base Lewis-McChord in Washington state to determine the level of his guilt and whether he acted with premeditation, as prosecutors said, or on impulse, as the defense has argued.
The judge in the case, Army Colonel David Conn, asked Russell, who appeared at a brief morning hearing in green military dress, to stand and gave his ruling. He did not provide further details.
Russell's state of mind before, during and after the attack, one of the worst incidents of soldier-on-soldier violence in the Iraq war, has been central to legal proceedings over the past year at the Pacific Northwest military base.
In his ruling, the judge ultimately sided with prosecutors who said Russell tried to gain a quick exit from the Army and had then sought revenge on a mental health worker who would not help him achieve that goal.
The mandatory sentence for even one count of premeditated murder is life in prison, and at issue going forward is whether Russell will ever be eligible for parole. Both sides will present arguments, and Conn is likely to rule on that by week's end.
Prosecutors have argued that Russell had more than 40 minutes to consider his actions as he drove to the clinic in a stolen Ford SUV and M16-A2 rifle, and witnesses have testified to how he removed identification tags and the gun's optic, and had a stone-faced demeanor as he stalked to the clinic.
An Army forensic science officer who analyzed the scene after the attack testified that Russell killed with the tactical precision of a trained soldier.
Defense attorneys said Russell's mental health, severely weakened by several combat tours, deteriorated further and that he was suicidal prior to the attack and provoked to violence by maltreatment at the hands of healthcare workers he sought for help at Camp Liberty.
A forensic psychiatrist, Dr. Robert Sadoff of the University of Pennsylvania, concluded that Russell suffered from post-traumatic stress disorder and psychosis at the time of the shootings and had death wishes related to his illnesses.