Behenna's supporters believed he was denied the right to a fair trial when a prosecution witness who could confirm Behenna's account of the events surrounding Mansur's death was not permitted to testify. The witness was Dr. Herbert MacDonell, who says he told the prosecution that based on the evidence, Mansur must have been reaching for Behenna's gun when he was shot, making Behenna's actions in shooting Mansur justified. The defense attorneys were not informed about the possible exculpatory evidence until after Behenna was convicted when MacDonnell approached them.
Behenna is currently serving a 15 year prison term in Ft. Leavenworth. The details of this controvery can be accessed here.