Family members of a man who was shot dead by air marshals in Miami after allegedly announcing he had a bomb demanded an explanation of the killing from U.S. authorities Friday.

"I can't understand why U.S. authorities killed my son in this way. He was not a terrorist," Carlos Alpizar, the 72-year old father of Rigoberto Alpizar told The Associated Press in the family home in Rio Claro de Golfito, near the Panama border about 190 miles south of Costa Rica's capital, San Jose.

"Rigoberto loved everything about his second country," he said "And look, they killed him like a dog."

Rigoberto Alpizar, 44, left his native Costa Rica for the United States two decades ago. He became a naturalized U.S. citizen and worked for the U.S. chain Home Depot.

Federal officials say Alpizar made a bomb threat in the jetway, after running out of the plane. They said they opened fire because Alpizar ignored their orders to stop, instead reaching into his backpack.

Alpizar's brother, named Carlos Alpizar like his father, said the shooting was unjustifiable.

"They say he was carrying a bomb, but Rigoberto and his wife had passed the security zone, they were checked thoroughly and still they killed him," he said.

Alpizar's remains will be buried next to those of his mother, Francisca Medina, in a cemetery in Cariari de Pococi, about 40 miles northeast of San Jose.

"We want them to rest together," said the elder Carlos Alpizar, explaining that the family had reached an agreement with Rigoberto Alpizar's wife, U.S. citizen Anne Buechner, to bury Rigoberto in his homeland.

Buechner told witnesses and police that Rigoberto suffered from bipolar mental disorder and was off his medication when he became agitated and began running through the aisles of a commercial airliner that was about to depart from Miami to Orlando on Wednesday.

However on Thursday, another brother Rolando Alpizar told Costa Rican Channel 7 television that family members were not aware that his brother had any mental problems and he described Rigoberto as "a very honest, very hardworking, responsible person."

The father said his son called him often and came home last July to accompany him to the doctor for a heart problem. Before he returned to the United States, he left notes throughout the house to remind his father to take his medication.

President Abel Pacheco, who is a psychiatrist, told radio station Nuestra Voz on Thursday that he would seek an investigation into the matter. He remarked that people in the United States "are living in a state of collective hysteria and if the police say, 'Get down,' you get down."

Costa Rican Foreign Minister Roberto Tovar said the government would look into possibly helping the family with the cost of transferring Alpizar's body back to his homeland.