GRAFENWÖHR, Germany — Two soldiers who helped Army investigators gather evidence about the alleged unlawful killing of four Iraqi detainees also will face charges for their alleged roles in the incident.

A Joint Multinational Training Command press statement issued Thursday said two 172nd Infantry Brigade soldiers — Staff Sgt. Jess Cunningham, 27, and Sgt. Charles Quigley, 28 — will face courts-martial on charges of conspiracy to commit premeditated murder.

The charges are related to an incident that occurred in April or May of 2007 in Baghdad, according to an Army release.

Article 32 hearings for the two soldiers were held in August in Vilseck, Germany.

According to court testimony at the time, Cunningham and Quigley were in the area when three fellow soldiers — 1st Sgt. John E. Hatley, Sgt. 1st Class Joseph P. Mayo and Sgt. Michael P. Leahy Jr. — fatally shot four unarmed Iraqi detainees near a canal in southwest Baghdad.

At least 15 soldiers were at or near the site of the killings, according to witnesses’ recollections of the incident.

Mayo and Leahy confessed their roles to Army investigators in January, according to sworn statements that were entered into evidence during the Articles 32. Hatley apparently didn’t make a statement to investigators.

According to witnesses at the Article 32, Hatley instructed his soldiers to keep quiet about the killings, and, apparently, they did for at least eight months.

But, according to testimony, Cunningham blew the whistle on the alleged shooting of the Iraqis in January of 2008.

At the time of the alleged incident, all the soldiers involved were part of the 1st Battalion, 18th Infantry Regiment.

The Army release said JMTC Commander Gen. David. R. Hogg referred the charges to court-martial on Monday following completion of the Article 32 investigation.

A date for the trials has not been scheduled at this time, the statement said.