No connection to the Alpha attack has been reported by the government, and Justice officials say they cannot comment. But investigators told Alpha veterans recently that they were looking into it; and the troops are thrilled at even a chance of closure.
The Iraqi citizen, Waad Ramadan Alwan, 31, is in federal custody after pleading guilty in December to rigging bombs against American troops in Iraq and also trying to ship weapons from the United States back to Iraq.
Federal agents handling the investigation apparently were unaware of any possible Alpha link until a couple of Alpha soldiers read about Alwan's guilty plea on the Internet and called the FBI's attention to the attack on their unit.
"I think there is an extremely high chance that this guy was part of a [terrorist] cell that was waging war against us when we were there," said Staff Sgt. Joshua Hedetniemi, a Guard recruiter who was one of the men to call investigators.
Hedetniemi said he and "some of the boys" will fly to Bowling Green, Ky., when Alwan is sentenced in October.
Retired Sgt. First Class Trenton Williams, once platoon sergeant for two of the men killed, said he still lives with the shock of what happened.
"When you're over there, you can't put a face on your enemy. It's so ambiguous; you don't know who is who," said Williams, who works at the Veterans Administration. "You would feel a lot better about it if you actually got the guys who did it."
Alpha Company, based in Northeast Philadelphia, lost a total of six soldiers while serving in Iraq in 2004 and 2005. The deaths occurred in a four-day period at the height of the insurgency.
On Aug. 9, 2005, Alpha was the quick-reaction force for Task Force Dragoon, an 800-man battalion at Forward Operating Base Summerall 110 miles north of Baghdad.
Sixteen soldiers and two civilian dog handlers were sent out to investigate reports of insurgents firing grenades at truck convoys on the main supply route.
The men, in four armored humvees, rolled into an ambush. The four killed were all in the same humvee, ripped apart by the explosion of three 155mm shells wired together and ignited by a cellphone signal.
They were Pfc. Nathaniel DeTample, 19, of Morrisville, a student at Shippensburg University; Spec. Gennaro Pellegrini, 31, a Philadelphia police officer; Spec. Francis J. Straub Jr., 24, of Philadelphia, an employee of United Parcel Service; and Spec. John Kulick, 35, of Harleysville, a full-time firefighter in Whitpain and the father of a 9-year-old girl.
Two other Alpha soldiers, Spec. Kurt E. Krout, 43, of Spinnerstown, and Sgt. Brahim J. Jeffcoat, 25, of Philadelphia, had been killed three days earlier in a blast near Samarra. That attack was 60 miles from Beiji, outside of Task Force Dragoon's area of operations.
Kimberly DeTample, Nathaniel's mother, said even hearing word of the Alwan investigation caused her emotional pain. But she said she'd be glad for any resolution to the mystery of her son's death.
"I just assumed they would never figure out who did it. It's just one of those things in a war that happens," she said.
Alwan's name - and that of an alleged coconspirator, Mohanad Shareef Hammadi, 25 - surfaced publicly when the Justice Department announced their arrest last May. Hammadi awaits trial.
Calling it a breakthrough against terrorism, the government revealed that agents had been recording Alwan and Hammadi for months as they plotted with an FBI informant to ship cash and weapons - including Stinger missiles, C4 explosives, and grenade launchers - to extremists in Iraq.
The scheme was an FBI setup. The government said no weapons or cash went abroad.
In the course of the investigation, Alwan was heard telling the informant that he had worked at the power plant in Beiji - Alpha's patrol area - and belonged to an insurgent group that planted bombs almost daily.
"Alwan later explained that he was very good with a sniper rifle and that his 'lunch and dinner' would be an American," FBI Special Agent Richard Glenn said in a court affidavit.
(Retired Capt. Anthony Callum, commander of Alpha Company, said he remembers only one member of Task Force Dragoon being killed by a sniper.)
The Department of Homeland Security has not explained how Alwan or Hammadi got into the United States as refugees in 2009.
Officials said in December that, since the inception of an Iraqi refugee program in 2007, more than 62,000 Iraqis had been admitted. Many were translators who had worked with American forces.
The Justice Department has reported no other discovered extremists among the admitted refugees, but Homeland Security promised Congress it would do a tighter job of screening.
Daniel Cosgrove, a Homeland Security spokesman, said he was barred by law from discussing the status of any particular refugee, and could make no comment on Alwan or Hammadi.
Court-appointed lawyers for the pair did not return calls seeking comment.
Alwan's statements to the informant about his insurgent activities in Iraq were backed up when the FBI found physical evidence of that.
Records show that after his arrest, the FBI matched his fingerprints to an unexploded bomb made of artillery shells that was found with wires sticking up from the ground near the Alpha Company base on Sept. 1, 2005, three weeks after the fatal Alpha attack.
The defused explosive had sat with thousands of other bombs and bomb parts at an FBI lab in Quantico, Va. After Alwan came under investigation, officials ordered all of the pieces to be dusted for fingerprints.
Two of Alwan's showed up on a cordless telephone rigged as a triggering device.
Hammadi, whom Alwan recruited into the United States-to-Iraq exporting scheme, also allegedly told the FBI informant that he had a history as an Iraq insurgent.
Alwan, at one point, described Hammadi as a younger relative from al-Siniyah.
Al-Siniyah - or as-Siniyah, as it was known to U.S. troops - was the exact location of Forward Operating Base Summerall.
Edward Greene, an Alpha veteran, said he felt as if he'd been hit by a train when he learned of the close proximity - in time, place, and bomb method - between the attack on his unit and the activities Alwan already had admitted.
The former Army specialist, a truck driver in South Jersey, said, "I was amazed."
Contact Tom Infield at 610-313-8205 or email@example.com, or follow on Twitter @tinfield.