MADISON, Neb. -- The holdup men in one of the nation's deadliest bank robberies walked in with guns blazing, and within 40 seconds all five victims had been shot in the head, a police officer testified Friday.

Capt. Steve Hecker's dramatic description of the chaos inside the U.S. Bank branch came as northeast Nebraska suffered another blow: Authorities said a state trooper who stopped one of the suspects last week but failed to learn the man was carrying a stolen gun had killed himself, leaving behind a wife and six young children.

"This tragedy only compounds yesterday's tragedy," Gov. Mike Johanns said during a somber news conference in Lincoln.

Hecker testified during the first court appearance for the four suspects. He said one was asked why they opened fire at the U.S. Bank branch, and the man would say only, "It went to hell in the bank."

All four men were denied bail.

According to Hecker, one of the suspects cased the inside of the bank in nearby Norfolk, then walked out and used a walkie-talkie to relay the location of the employees to the other three. They started shooting as soon as they stormed in.

The three alleged gunmen were caught a few hours later in a stolen pickup after stopping at a gas station 75 miles away. A fourth suspect, the alleged scout, was arrested late Thursday. All are from the area.

Each suspect faces five counts of first-degree murder, which carries a potential death sentence in Nebraska.

About 50 people -- mostly friends of the suspects and relatives of the four bank employees and one customer who were killed -- packed the 30-seat courtroom. The customer's college-age daughter wept in the hallway before the hearing and sobbed in the courtroom every time her mother's name was mentioned.

The suspects sat stoically throughout the hearing, one of them yawning several times. All asked for court-appointed attorneys.

Hecker said the suspects had planned the holdup for at least two weeks, casing the bank several times. The officer then described what he saw on a bank surveillance video:

The gunmen systematically spread out as they came in, two going to offices on either side of the entrance. The third went to the tellers' counter, where customer Evonne Tuttle, 37, was among the first to be shot. The gunmen then hurdled the counter. The slayings of the four employees are not visible on the tape.

The suspects were identified as Jose Sandoval, 23, Jorge Galindo, 21, Erick Fernando Vela, 21, and Gabriel Rodriguez, 26.

Driver changed mind

Investigators believe Rodriguez had been posted outside the bank in his car until the robbery went awry and he drove off, Mayor Gordon D. Adams said.

"He must have been the getaway driver, and had a change of heart when he heard the gunshots," Adams said.

The employees killed were Lola Elwood, 43, Jo Mausbach, 42, Lisa Bryant, 29, and Samuel Sun, 50.

No money was recovered on the men or along their suspected escape route, Norfolk police chief Bill Mizner said.