Fretful Passenger, Turmoil on Jet and Fatal Shots

MIAMI, Dec. 8 - Lingering near his departure gate at Miami International Airport on Wednesday, Rigoberto Alpizar appeared flustered and loath to make the last, brief leg of his long journey home.
"He was standing up against the wall with his wife," said Alan Tirpak, a fellow passenger on American Airlines Flight 924 to Orlando, who spotted Mr. Alpizar next to the passageway leading to their plane around 2 p.m. "He looked agitated - had a very nervous, agitated look to him. As I walked past them, his wife told him, 'Let's let these people get on first. It will be O.K.' "
Minutes later, after the couple had found their seats at the back of the aircraft and Mr. Tirpak had settled into his seat near first class, Mr. Alpizar ran through the aisle toward the front of the plane, almost knocking over a flight attendant, "trying desperately" to get off with his wife at his heels, recalled another passenger, Natalia Cayon.
When he ignored calls from two federal marshals to stop, he was gunned down in the passageway.
The marshals said Mr. Alpizar had said he had a bomb.
Relatives said the couple had been returning from a stressful vacation. Mr. Alpizar's wife, Anne Buechner, had been robbed in Peru, losing her wallet, passport, laptop computer and cellphone, said her sister-in-law, Kelley Buechner of Milwaukee.
"That really upset Rigo," Ms. Buechner said in an interview at her home, using the family's nickname for Mr. Alpizar, a Costa Rica native who became an American citizen a few years ago. "Anne was robbed in Peru, and it was very unsettling to them both."
Mr. Tirpak, flying home from a business trip, said that as the couple waited to board Mr. Alpizar had begun singing the refrain from the old spiritual, "Let My People Go."
The Miami-Dade Police Department, which is investigating whether the shooting was justified, said it had interviewed more than 100 passengers and crew members from Flight 924 and that preliminary evidence suggested Mr. Alpizar had repeatedly refused to surrender. The White House, meanwhile, defended the actions of the air marshals.
"I don't think anyone wants to see it come to a situation like this," said Scott McClellan, the White House spokesman. "But these marshals appear to have acted in a way that's consistent with the extensive training that they have received. And we'll see what the investigation shows, and lessons learned from that will be applied to future training and protocol."
Chief Willie Marshall, who leads the Miami-Dade criminal investigations unit, said Mr. Alpizar had run off the plane and, while on the passageway, reached into a bag that was "strapped to his chest." That was when both air marshals opened fire with multiple shots, he said.
Chief Marshall said that homicide detectives had interviewed Ms. Buechner throughout the night and that she had told them her husband had received a diagnosis of bipolar disorder roughly a decade ago. "She provided us some very valuable information and insight about what was going on with her husband," he said. "She told us he had not taken his medication recently."
Though Chief Marshall said the couple had been on a vacation, a neighbor described it as a missionary trip and said both were frequent churchgoers.
Both marshals aboard Flight 924 were hired in 2002, said David M. Adams, a spokesman for the Federal Air Marshal Service. One was a four-year veteran of the Border Patrol and spoke fluent Spanish, he said, and the other had worked for two years as a customs inspector.
Mr. Adams said he did not know what language the air marshals had used to address Mr. Alpizar. But another marshal, who spoke on the condition of anonymity because air marshals have been threatened with dismissal for speaking to the news media, said he understood that instructions had been given in both Spanish and English.
One marshal said that air marshals are typically the first to board planes, even before the disabled and travelers with young children, and that Wednesday's incident had occurred before the plane door was closed. He theorized that the marshals had probably not had a chance to observe Mr. Alpizar in the boarding lounge.
Chief Marshall would not reveal the specifics of his agency's interviews with people who were on the aircraft, including whether any had said they heard Mr. Alpizar threaten that he had a bomb. But Mark Raynor, an American Airlines pilot and local union official in Miami, said an account he heard from the plane's captain had supported law enforcement accounts of the shooting.
Mr. Raynor said the captain had been outside the cockpit at the time of the shooting and witnessed it, but the first officer had been inside the cockpit and had seen nothing.
Chief Marshall said detectives were waiting to interview the two air marshals and hoped to do so on Thursday. The marshals were placed on paid leave on Thursday, pending the outcome of an internal investigation, officials said.
Ms. Buechner returned Thursday to the white ranch home she had shared with her husband of 18 years in Maitland, outside Orlando. Relatives who had flown to Miami drove her the roughly four hours home after she had finished talking to detectives, Chief Marshall said.
Ms. Buechner did not speak to reporters who had gathered outside the home on a bleak, rainy day, but her brother, Steven Buechner of Milwaukee, and her sister, Jeanne Jentsch, of Sheboygan, Wis., emerged to read a short statement and ask the news media to leave the family alone.
"Rigo Alpizar was a loving, gentle and caring husband, uncle, brother, son and friend," Ms. Buechner said. "He was born in Costa Rica and became a proud American citizen several years ago. He will be sorely missed by all who knew him."
Kelley Buechner was more forthcoming as she talked to a reporter while drinking coffee in her Milwaukee living room, the television news droning in the background.
She said Mr. Alpizar had learned English after moving to Florida from Costa Rica. She described him as a joyous, playful man who enjoyed working in his garden and taking his niece to Disney World and the beach when she visited every summer.
"It's not the Rigo we knew," she said. "This person who you are seeing is not our Rigo."
Until now, Kelley Buechner said, she had never heard that her brother-in-law was bipolar, only that he had had "a chemical imbalance" for which he took vitamins. She said she had never known Mr. Alpizar to stop taking his medication.
If he was bipolar, she said, it was fitting of Anne Buechner not to discuss it with family. "She's the type who doesn't want to burden people with her problems," Kelley Buechner said.
Her daughter, Ciara, 11, described Mr. Alpizar as a gentle uncle whom she could not imagine hurting anyone. "If I caught lizards and accidentally killed one, he would almost be kind of sad," Ciara said of her annual visits to Florida. "He would say, 'What if that happened to you?' "