On September 18, 2009, the Virginia Supreme Court upheld death sentences imposed on Wiliam Morva for the murders of a Montgomery County hospital security guard and a deputy sheriff during the course of an escape from jail.  http://www.courts.state.va.us/opinions/opnscvwp/1090186.pdf. 

The primary issue on appeal concerned the trial court's refusal to appoint Dr. Mark Cunningham, a leading researcher on prison violence risk assessment,  at Morva's capital sentencing hearing.  Morva's defense had sought to present such an expert risk assessment as a means of rebutting the prosecution's argument that he should be executed because of the risk that he would harm or kill prison or law enforcement officers if he were sentenced to life imprisonment.  Although defense counsel made clear that the proposed risk assessment would take into account Morva's own background and the facts of his offense, the state supreme court majority followed a series of its prior cases (including Walker, Bell,  and Porter) to hold that the proposed risk assessment would have been irrelevant and inadmissible because Dr. Cunningham ALSO proposed to take into account those aspects of long-term imprisonment which reduce the risk of violent recidivism by the defendant.  Two dissenting justices (Justice Koontz, joined by Justice Keenan) argued that the exclusion of such risk assessment testimony violated due process because it unfairly prevented Morva from showing that he could be imprisoned for life without creating any undue risk of further violence.  
 
This decision clearly establishes Virginia as the only death penalty state that categorically bars defendants from attempting to rebut allegations of dangerousness by offering scientific prison violence risk assessment evidence.