I didn't think those guys made mistakes like that. I've known several. They were all cautious guys and well very trained regarding their weapons. This really surprised me. Yahoo! News Guns drove fatal FBI bank heist probe By DAVID PORTER, Associated Press WriterSat Apr 7, 12:50 PM ET The bank robbery investigation had gained intensity because of the increasingly brazen and violent nature of the crimes, with shots fired inside at least three of the institutions. But when three of the suspects were confronted by FBI agents, authorities say the armed men didn't fire a shot. Instead, the FBI says it appears that one of their own, a veteran of major investigations, was killed when a fellow agent's weapon accidentally discharged. In the past two months, banks had been held up in four central New Jersey towns. The biggest take was about $28,000. Despite shots fired in three of the banks, only one person was injured, a teller struck by flying glass and a ricocheting bullet fragment. Carrie Brzezinski, the FBI's lead investigator on the case, said it was the first case she had investigated in which weapons were fired inside a bank. "I've been doing violent crime in the Newark division for 16 years, probably more bank robberies than anything else, and this is unprecedented," she said. The willingness of the robbers to use their weapons created a "worst-case scenario, as far as danger and violence, both to agent personnel, as well as to the public and bank employees," said William Rehder, a Los Angeles-based security consultant who spent 33 years in the FBI, most of them investigating bank robberies. "This was as intense of a bank robbery investigation as there is," Rehder said. On Thursday, FBI agents confronted three men outside a PNC Bank in Readington Township. Wilfredo Berrios, 28, and Michael Cruz, 21, were arrested and agents confiscated two assault rifles and a handgun. A third man, Francisco Herrera-Genao, 22, fled on foot and was captured Friday morning after spending the night in nearby woods. After his arrest, Cruz admitted the men were attempting to rob the Readington bank, according to the complaint. Cruz also said he, Berrios, Herrera-Genao and Efrain Lynn, 21, had committed a March 16 bank robbery in South Brunswick, according to a second federal complaint. All the men are from New Brunswick. According to Brzezinski, one of the suspects was overheard saying to another on Thursday that they "were prepared to go down in a blaze of glory." "This was a rush for them, in my opinion," she said. "They didn't need the money, based on what they'd already gotten a few weeks ago. This was their thing and as far as they were concerned, they were getting away with it." The fourth man, Lynn, was arrested at another location Thursday in connection with one of the earlier holdups, federal prosecutors said. The FBI had been on their trail since early last month, after the third of four robberies in central New Jersey. The federal criminal complaint against the three men says a surveillance camera caught masked gunmen getting into a rental car that was eventually traced to Berrios. While authorities said Berrios, Cruz and Herrera-Genao didn't fire their weapons Thursday, FBI Agent Barry Lee Bush was killed. "Preliminarily, information suggests the agent may have been fatally wounded as a result of the accidental discharge of another agent's weapon during a dynamic arrest situation," the FBI said in a statement. The FBI hasn't said where Bush was hit, who fired or how many times he was shot. "He was old-time FBI â€” he loved to work the streets and he hated to do paperwork," said Jack Jupin, a supervising special agent in the Newark office. "He always wanted to take the bad guys off the streets, and that's what he died doing." Bush, 52, also had played a key role in the prosecution of James C. Kopp, an anti-abortion opponent convicted of killing Buffalo-area obstetrician Dr. Barnett A. Slepian in 1998. While searching a Jersey City apartment Kopp had rented under the name "Clyde Swenson," Bush found a notebook that contained the doctor's name and office telephone number. The same year, Bush collected evidence at the scene of the U.S. Embassy bombing in Nairobi, Kenya, as the team leader for the Newark Evidence Response Team. He and another agent oversaw the search of a building near the embassy.