A sniper killed the male suspect while a female suspect was in custody, said Osceola County Sheriff Bob Hansell. Four hostages were not injured.
The suspects had escaped the Mercantile Bank, a mile west of Walt Disney World, with their only remaining hostage after authorities blasted through the rear door using an explosive device.
They made it less than a mile before police spikes on the ground flattened all four of the car's tires, reports CBS News correspondent Mark Strassmann. Cornered, and with no other option left, the robbers and their hostage drove back to the bank.
"They were making statements that the last hostage was their only leverage. They were not going to release her," Hansell said on CBS News' The Early Show.
The male suspect then "used the hostage again as a shield to get into another vehicle," Hansell said. "He tried to leave again and at that point he was taken down by one of our snipers."
Deputies had been using cell phones to negotiate with the suspects, who were wearing masks, wigs and coats.
The hostages said they were treated well and were not threatened with violence, Hansell said.
It was not immediately clear whether the suspects ever got any money.
Around 7:15 p.m., police blasted through the bank's rear door. The suspects escaped with a female hostage and drove away in a bank employee's car, but they traveled less than a mile before street barricades stopped them.
Shots were fired at deputies but nobody was hurt, police said.
The suspects had been holed up in the bank since Tuesday morning. The first hostage was released when the robbers panicked when deputies arrived so quickly after the robbery, said sheriff's spokeswoman Twis Lizasuain.
The second was freed in an exchange.
"They asked for cigarettes, of all things. And they asked for a pack of cigarettes and they would release another hostage. We complied and they did," Hansell told Early Show co-anchor Hannah Storm.
The third was released after deputies agreed to back their vehicles a few feet farther away from the bank, Lizasuain said.
Police did not release the names of the suspects or the hostages.
The same bank was robbed Nov. 16, and investigators are still looking for two suspects, Lizasuain said.
It was also the second violent incident in the area in as many days. A man shot the driver of a vehicle he was trying to carjack, then stole at least two other vehicles and led deputies on a three-hour chase before shooting himself in the head.
Those two incidents and the extensive live television coverage of them "could destroy tourism here for a while," Valerie Blakeway, who lives part of the year in the area, told the Orlando Sentinel.