WASHINGTON — U.S. Army Spc. Israel Rivera had just returned to duty at the Abu Ghraib prison in Iraq last October after minor surgery to remove shrapnel from his face. He was checking his e-mail, he recalls, when another military intelligence soldier approached.
"Hey Izzy, did you hear about those detainees that raped that one kid?" asked the other soldier, Spc. Armin J. Cruz.
Rivera hadn't heard of the incident and asked what was going to happen to the prisoners. Cruz, Rivera said, responded with an invitation: "Do you want to go see what's happening?"
The two army intelligence analysts from a reserve unit in Texas walked over to the isolation cellblock at Abu Ghraib and into the middle of the prison abuse scandal that came to light in April. Their faces were among those captured in disturbing photographs of inmates being mistreated.
In a telephone interview with The Times, Rivera described his involvement in the case for the first time, saying that he visited the cellblock largely out of curiosity and that he was stunned by what he saw: detainees being stripped naked, made to crawl on their stomachs and chained into a ball of limbs and flesh on the prison floor.
Rivera, 20, is the first military intelligence soldier to come forward publicly and say that he witnessed a fellow intelligence soldier, Cruz, taking part in the abuse of prisoners in the isolation cellblock at Abu Ghraib. Cruz has also been cited in testimony by Sgt. Samuel J. Provance III, another intelligence officer, who said Cruz "was known to bang on the table, yell, scream, and maybe assaulted detainees during interrogations in the booth."
Cruz could not be reached for comment this week.
Because they are among only a handful of intelligence soldiers directly tied to the abuse in photographs, Rivera and Cruz are potentially important witnesses for military investigators seeking to determine the scope of the scandal -- specifically whether the torture of detainees had any connection to the interrogation operation at Abu Ghraib.
Rivera disputed such claims, saying the abuse he witnessed had nothing to do with "softening up" prisoners to get information from them.
He insisted that his superiors did not know about the abuse, let alone sanction it.
Rivera said that as he got ready to leave the cellblock amid anguished pleas for help from the prisoners, Cruz stopped him to make sure he didn't plan to talk.
"Before I walked out of that bay, he looked at me and asked me, 'Izzy, you're not going to tell anybody, are you?' " Rivera said, speaking by telephone from Baghdad this week.
"And I looked at him and I said: 'No, absolutely not, Cruz. You have nothing to worry about.' "
Rivera said he never informed his superiors and still hasn't shared his account with military investigators.
When he met with an Army Criminal Investigation Division agent in January, he refused to talk unless he was provided with an attorney.
"The big reason I'm doing this [speaking publicly] is there's a big sense of guilt that I have," Rivera said. "I didn't know there was a huge conspiracy [of abuse at Abu Ghraib], but I did know about that one night.... I should have said to my sergeant, 'Hey Sergeant, I saw this,' and a lot of it would have been dealt with if I had."
The episode Rivera witnessed came about two weeks before some of the most serious abuses took place, including nude prisoners being stacked up in pyramids or forced to masturbate in front of guards.
Rivera said he had not been charged and was not certain of his legal status. He and Cruz are both members of the 321st Military Intelligence Battalion in Austin, Texas, but they were transferred to a Connecticut unit before being deployed to Iraq.
Though the unit returned to the United States months ago, Rivera and Cruz have had their tours involuntarily extended. Rivera said his orders now keep him in Iraq until November.
Late last November, officials said, Cruz and a female interrogator were disciplined after forcing an uncooperative detainee to strip naked.
Rivera's account is the most detailed description to date of prisoner abuse that is believed to have occurred Oct. 25. According to military records, Rivera appears in photographs taken that night that show as many as seven U.S. soldiers and one civilian interpreter huddled around three naked detainees on the floor.
Several of the soldiers are MPs, including Cpl. Charles A. Graner Jr., who faces court-martial and has been portrayed as a ringleader in the abuses.
But Rivera was among at least four intelligence personnel at the scene, including Cruz; Spc. Roman Krol, an Army interrogator; and Adel L. Nakhla, a civilian interpreter employed by Titan Corp.
Several of the seven MPs charged in the case have said they were encouraged or directed by interrogators to mistreat prisoners as a means of softening them up for questioning.