Washington ? On March 12, a 15-year-old Iraqi girl was raped, and she and her father, mother and sister were gunned down in their home.

Three months later, three U.S. soldiers were slain by insurgents. One was shot and two others were kidnapped, killed and their bodies mutilated in what a group linked to al-Qaida declared was retribution for the attack on the Iraqi family.

Four soldiers and one former soldier have now been charged in connection with the rape and homicides. Another soldier has been charged with failing to report the incident.

One of the questions surrounding two of the most dreadful incidents of the war is whether they are connected. Did the alleged rape and murder of Iraqi civilians by U.S. troops beget the torture and slaying of their own comrades?

Earlier this month, al-Qaida in Iraq posted a gruesome video on the Internet showing the soldiers’ disfigured bodies, and said they were executed to “avenge” the rape and homicides. Army investigators deny al-Qaida’s claims and say there is no connection between the incidents, though military spokesmen did not respond to questions last week about why they believe that.

Soldiers connected

Whether or not the episodes are connected, it is clear the soldiers themselves were connected, bound by their experiences in combat. Members of the same unit, many of them were friends with one another. The alleged rape and homicides came to light, investigators said, only when some of the soldiers underwent a “combat stress debriefing” prompted by the deaths of the three soldiers.

The soldiers were all members of 1st Platoon, B Company, 1st Battalion, 502nd Infantry Regiment, assigned to the 101st Airborne Division.

“There’s nine guys on a squad,” said Nancy Hess, mother of Pfc. Jesse Spielman, 21, who is one of the five charged in the crimes. “Three of them were killed. Six of them are being charged.”

The three were Spec. David Babineau, shot during an ambush in which Pfc. Kristian Menchaca and Pfc. Thomas Tucker were kidnapped. Menchaca was found with his throat slit, and he was so badly beaten he was unrecognizable. Tucker had been beheaded.

In addition to Spielman, those charged are Sgt. Paul Cortez, Spec. James Barker, Pfc. Bryan Howard and a former private, Steven Green, who had been discharged from the military for a personality disorder. Sgt. Anthony Yribe has been charged for failing to report the incident.

Alleged rape, murders

Three months earlier, on March 12, soldiers from their platoon were drinking alcohol against orders and decided to rape the Iraqi girl they had seen pass through their checkpoint, authorities said. The girl and her family lived nearby, and the soldiers went into the house, raped the girl, shot the family and set the house on fire, according to the charges. Initially, they told their superiors insurgents had killed the family.

Despite the terrible crime with which they are charged, the soldiers were in many ways typical military recruits, friends and relatives said.

Some had had brushes with the law. Others had left high school. They went by nicknames such as Vanilla, Bunky and the No-Town Soldier. They came from little towns and small cities. On their MySpace pages, they played heavy metal music, appeared brash, fantasized about one-night stands with movie stars, boasted about their cars and talked trash about their enemies in Iraq.

The soldiers

Spielman’s friends in his home town of Chambersburg, Pa., told the local newspaper he was a fun-loving young man nicknamed “Vanilla” after, on a dare, he cut his hair to look like 1990s pop star Vanilla Ice. A 2002 high school graduate, he took technical courses in high school and made the honor roll his senior year, they said.

Green’s life was apparently the most troubled of all the indicted. Raised mostly in Midland, Texas, his parents divorced when he was 4. When he was 15, his mother was jailed for six months for drunken driving. Two years later, Green dropped out of Coleman High School, an institution for students who have trouble in regular school. Days before he joined the Army last year, Green spent three days in custody after being arrested for underage possession of alcohol. Previously, he had been arrested for possession of drug paraphernalia.

Green received an honorable discharge and left the army in mid-May after 11 months. He was discharged because of an “anti-social personality disorder,” according to military officials and court documents, although officials said his discharge was not related to the alleged crime.

Barker, 23, was raised a Jehovah’s Witness in Fresno, Calif. Barker worked as a go-cart attendant before joining the Army, his friends said. He has two children with a wife he is divorcing, and a newborn at home with a girlfriend. Friends call him “Bunky.”

Friends described Cortez as a quiet man of deeply religious beliefs who favored skateboarding and track in the Southern California town of Barstow, where he was raised. Cortez’s mother, Pat Adams, raised her son in motels in the area and lives in one now. She declined to speak with reporters.

Bryan Howard spent his high school years in JROTC, where he excelled, his father said.

Howard’s friend in JROTC, Michael Doke, said Howard “showed up early every day and reported in after school. We also did color guard together and went to basketball games and football games to do the flag.”