George Wright is seen in a post office in Praia das Macas, Portugal, in 2000.  (Photo: AP Photo/Noticias de Colares)

The FBI had once relegated the capture of convicted killer George Wright to the “cold case” files, but since his arrest Monday in Portugal that case is closer to being closed.

Wright disappeared after a 1972 hijacking by the Black Liberation Army of a U.S. plane to Algeria. He had previously escaped from a New Jersey jail while serving time for a separate murder 10 years prior. Wright had evaded authorizes for four decades, traveling from New Jersey to Detroit to Algeria to France to Guinea-Bissau, a tiny island off the west coast of Africa, before he was arrested. A fingerprint on Wright's Portuguese ID card led a U.S. fugitive task force to the killer.

Wright lived in Guinea-Bissau for at least two decades under his real name and even made acquaintances with U.S. embassy officials. Although seemingly inconceivable, FBI officials say it’s not surprising Wright lived on the lam for so long.

"Obviously communication abilities were much less back in the '70s and the '80s than they are today," said  Michael Ward, head of the FBI in Newark, New Jersey, told the Associated Press. "You're dealing with someone with a common name who is living a low-key lifestyle and those factors would have contributed to him going unnoticed at the time."

John Blacken, a retired U.S. ambassador to Guinea-Bissau who knew Wright and his wife, told the AP that he had no idea of Wright’s fugitive past. While serving as an ambassador from 1986 to 1989, Blacken said he was never alerted by U.S. law enforcement officials about Wright's background. He said Wright’s wife might have even worked on translation projects for the U.S. embassy.

An employee at the Guinea-Bissau embassy in Lisbon said no one was available to comment on whether Wright obtained citizenship from the African nation, but doing so in the 1980s was relatively easy for foreigners.

Wright is being held in Lisbon, the capital of Portugal, pending extradition hearings. He will likely stay in custody for at least several weeks while his lawyer and lawyers for the United States present their legal arguments, the president of the Lisbon court told the AP.

Back in 1970, Wright and three other men escaped from Bayside State Prison in Leesburg, New Jersey. Subsequent to his escape, Wright traveled to Detroit and became affiliated with the Black Liberation Army. On July 31, 1972, five adults, accompanied by three small children, hijacked Delta flight 841 en route from Detroit to Miami. Subsequent investigation identified Wright as one of the hijackers.

Upon landing in Miami, Wright and his associates demanded a $1 million ransom in exchange for the passengers — the largest ransom of its kind at that time. After releasing the passengers, Wright and his associates forced the plane to fly to Boston for refueling and the addition of another pilot, and then proceeded across the Atlantic to Algeria where they sought asylum. At the request of the United States government, the money and plane were eventually seized and returned by Algeria to the Unites States. Wright and his associates were briefly taken into custody but were eventually released after a few days.

On May 26, 1976, Wright’s associates were located and arrested in Paris by the French National Police. The four adults were tried and convicted in French court. Since that time, George Wright has remained the lone fugitive, on the run since his escape on August 19, 1970.