The officer who shot and killed Pfc. David H. Sharrett II of Oakton in a friendly-fire incident in Iraq in 2008 should be terminated from the Army and stripped of a combat badge he received for a battle he fled, leaving the mortally wounded Sharrett and four other soldiers behind, military officials have ruled.

The move was revealed on the eve of what would have been Sharrett’s 32nd birthday, and was the result of four years of investigating and agitating by his father, David Sharrett Sr. , a retired English teacher at Langley and Chantilly high schools in Fairfax County.

At least four previous reviews by the Army had resulted in little more than reprimands for the officer, Capt. Timothy R. Hanson, now 33, who was promoted from lieutenant a year after the incident, and who had been allowed to transfer from active duty to a full-time Army Reserve job in his home state of Wisconsin.

“This is a vindication of our efforts to discover what happened and what did not happen,” the senior Sharrett said Monday. “This whole thing was about Dave, about giving him a voice. He acted honorably on the battlefield. He did everything he was supposed to do. And the ones who knew about this covered it up, acted cowardly.”

Hanson claimed in an Army probe last year that he didn’t know he had shot Sharrett, even as the investigating general repeatedly showed him overhead video of the two soldiers within feet of each other. Hanson said he needed to leave the battlefield to assist two wounded men and brief his commanders. The wounded men told the general that Hanson did not assist them, and Hanson apparently did not brief commanders or return to his unit, which remained on its mission for two additional days.

Hanson said earlier this year that he did not want to discuss the incident, but that he was sorry and wanted to apologize to the Sharrett family. He did not respond to requests for comment in recent days.

The Army sent an e-mail to David Sharrett Sr. last week saying that Army Secretary John McHugh had referred the awarding of Hanson’s Combat Infantryman Badge to the Army’s Human Resources Command for review. The e-mail reported that the command’s Army Awards Board had recommended revoking Hanson’s badge, and McHugh had approved that move.

The e-mail continued that McHugh, in late February, had ordered a review of Hanson’s actions by the U.S. Army Reserve Command, since Hanson is now a reserve. The reserve commander “initiated elimination proceedings against CPT Hanson. As a result, CPT Hanson is currently being processed for separation from the Army.”

Army officials declined to say whether the separation was honorable, though a dishonorable discharge would require court-martial proceedings. They also would not discuss why the move came more than four years after the incident.

Lt. Gen. Mark P. Hertling, who commanded the multinational forces in northern Iraq in 2008, said in an e-mail Monday that Sharrett was “incorrect about his perception about what the chain of command knew regarding Capt. Hanson’s actions the night of the fratricide, or after.” Hertling said the commanders’ focus was on the fratricide itself, “and how to prevent it from happening again,” not Hanson’s actions after the shooting.

On the freezing, dark morning of Jan. 16, 2008, during the U.S. military “surge” in Iraq, then-1st Lt. Hanson led a squad of seven soldiers to capture what was reported to be six unarmed “unidentified enemies.” The men were thought to be insurgents with al-Qaeda in Iraq, near the city of Balad. But the insurgents were heavily armed and erupted with gunfire while huddled inside a small thicket. Two American soldiers were killed and two more wounded, while Sharrett hit the ground within feet of the thicket.

Overhead video from a drone, two helicopters and two jets captured nearly all of what happened next: Sharrett stood, fired back into the thicket, and sprinted away from the enemy. Hanson, lying on his stomach, turned to his left and fired one shot into Sharrett’s left buttock from a distance of about six feet. Hanson then stood, ran from Sharrett and dropped to the ground again, pleading for aerial support while his men were too close for helicopters to fire on the thicket.

The moment when Hanson shot Sharrett was obscured by trees on the videos. But later, Hanson can be seen boarding a helicopter, which landed to carry two of his wounded men to a hospital, though Hanson was not injured.

Sharrett was alive when he was found 75 minutes after the shooting, but died soon after of massive internal bleeding from a severed femoral artery.

In February, after a story in The Washington Post, the Sharretts met with Army Secretary McHugh and the Army released Hanson’s military record, showing he had received a combat infantryman badge and was active in the Army Reserve. Further digging by Sharrett revealed the badge was issued to Hanson for the battle in which he killed Sharrett’s son. In April, the Army said it was reviewing the award.

Sharrett said that “I’m not sure that [McHugh] was fully briefed on the extent of how atrocious this situation was” before their February meeting. “He reacted the way the rest of the Army has not reacted. Finally, at the top, the lights went on and he thought it was time to do the right thing.”