VILSECK, Germany — U.S. soldiers who allegedly executed four detainees in Baghdad last year were frustrated that dangerous insurgents they had captured in the past were put back on the streets, according to witnesses who testified at a pretrial hearing in Vilseck this week.

An Article 32 investigation was held this week for Sgt. 1st Class Joseph P. Mayo on a charge of premeditated murder. Two other soldiers, 1st Sgt. John E. Hatley and Sgt. Michael P. Leahy Jr. also have been implicated in the alleged killings.

Company A, 1st Battalion, 18th Infantry Regiment soldiers who were with the accused when the alleged victims were detained testified that they found the four Iraqi men with a large cache of weapons, ammunition and military equipment, including night-vision goggles, body armor, grenades, machine guns and thousands of bullets.

Spc. Justin Lamanna, who was on the patrol that captured the detainees, said the men were found in possession of "a collection of crap that you are not allowed to have in a war zone if you are not an American."

Joshua Hartson, a former Army specialist who served alongside the accused in Iraq, testified via telephone from California on Thursday. He said Hatley pulled him aside after the men were detained.

According to Hartson: "Hatley said, ‘If we take these guys to the detainee facility they will be put right back out on the streets and they will do the same thing, so we are going to take care of them.’ He asked if I had a problem with it and I said, ‘No.’ "

Spc. Jonathon Shaffer, who was a gunner on Mayo’s Humvee in Iraq, told the hearing that it was extremely hard to get insurgents off the streets.

"You pretty much have to catch the person on camera to get them to go to jail," he said. "If they’ve killed a U.S. soldier it becomes easier to get them in there. If there is no American soldier killed and you catch these guys with a (weapons) cache, it is difficult to get them to stay in jail."

Sgt. Daniel Evoy, who claims he witnessed the execution of one of the Iraqis through the hatch of his Bradley fighting vehicle, said Company A’s base, at Combat Outpost Angry Dragon, faced daily attacks in the first months of 2007 from small arms, sniper fire, rocket-propelled grenades and mortars. Patrols were hit by roadside bombs, and several members of the unit were killed or wounded, he said.

"We’d catch them, and a month later they would be out. Sometimes it was a qualified sniper being put out on the streets to do his job – to shoot at us. I’m not going to say we wanted them dead, but we wanted them behind bars," he said.

Hartson said he guarded the detainees in the back of a Bradley fighting vehicle for several hours before they were killed.

One of the detainees, a giant who looked like he weighed more than 300 pounds, spoke English, he said.

"I asked him why he makes bombs. Does he kill Americans? He laughed. If he was laughing about it, I was pretty sure he was killing Americans," Hartson said.

"One guy started crying really bad. I could see his tears coming out of the back of the blindfold," he said, adding that he shared a cigarette with one of the detainees who gave him a string of prayer beads as a gift.

"I was told to get rid of them but they meant something to me so I decided to keep them. Iraq is a big part of my life and experiencing that and being able to sit there and talk to one of the individuals … it means a lot to me that I was probably the last person he talked to."

The Army’s investigating officer, Lt. Col. Erik Christianson, is considering whether the evidence presented in Mayo’s case is sufficient to proceed with a court-martial.