It was a murder on the New Jersey Turnpike - stunning violence near the New Brunswick exit.

Now, decades after Black Liberation Army leader Joanne Chesimard was sentenced for the 1973 killing of a state trooper, escaped prison, and surfaced in Cuba in 1984, she is first and foremost among the estimated 70 American fugitives harbored there whose apparent flouting of U.S. law is fuel for critics of recent efforts to restore U.S.-Cuba relations.

In December, 54 years after America severed diplomatic relations with Cuba, Presidents Obama and Raul Castro proposed a renewal of ties.

"We view any changes in relations with Cuba as an opportunity to bring [Chesimard] back," said New Jersey State Police Col. Rick Fuentes, "and stand by the reward" for her capture.

Chesimard, 67, the lone woman on the FBI's list of "wanted terrorists," has a $2 million bounty on her head.

Convicted in the shooting death of New Jersey State Trooper Werner Foerster, 34, during a traffic stop of a car in which she was a passenger, Chesimard - who adopted the name Assata Shakur and happens to be the aunt of slain rapper Tupac Shakur - is the poster child for critics who say the State Department must insist on her extradition as a condition of any fresh start with Cuba.

"It is a national disgrace that this president would even consider normalizing relations while they are harboring a terrorist-murderer who belongs in prison," Gov. Christie, an expected contender for the Republican nomination for president, said at a recent town hall meeting in New Hampshire.

In January, U.S. Sen. Robert Menendez (D., N.J.) wrote to Secretary of State John Kerry demanding Shakur's repatriation for "deplorable crimes."

Resolutions of the New Jersey Assembly call for her extradition; the state sheriff's association concurs.

Reviled by law enforcement and revered by Fidel Castro, who granted her political asylum, Shakur embodies America's commitment to retrieve its fugitives and Cuba's commitment to grant sanctuary to people it deems persecuted dissidents.

"Cuba not only is refusing to hand her over; it is refusing, at least publicly, to make the topic of extradition part of these negotiations," said Teishan Latner, a former fellow at New York University's Center for the United States and the Cold War, where he researched the relationship between Cuba and left wing groups in America for a forthcoming book.

Latner, who earned a master's degree in history from Temple University and a doctorate in history from the University of California-Irvine, currently is affiliated with the Center for Black Studies Research at the University of California-Santa Barbara.

He met Shakur at a conference on Cuban health care during his first visit to the island in 2004.

"Cuba considers her a folk hero who was persecuted by the U.S. government," he said. Cuba's evidence of her alleged persecution, he said: the absence of her fingerprints on the murder weapon; no residue on her hands to indicate she fired a gun; and her trial by an all-white jury.

Despite the half-century of severed relations, Cuba has cooperated on some expulsions of fugitives wanted in America.

In September 2011, Cuba handed over to U.S. authorities Denis Catania, 49, and Diana Camacho, 26, both formerly of Voorhees, to face kidnapping, murder, and arson charges in the death of Somerdale resident Ross Heimlich, 23, whose charred body was found in a torched car in Hammonton in 2010. The pair fled to Florida, then to various Caribbean nations before landing in Cuba.

In 2013, Cuba handed over a Florida couple, Joshua and Sharyn Hakken, who were wanted on charges that they had kidnapped their two young sons from maternal grandparents who had custody. The Hakkens fled with the children by sailboat to Havana.

Those examples are important, Latner said, because they show Cuba distinguishes between ordinary criminal activity in which it cooperates with U.S. law enforcement, and "cases where Cuba is motivated by political principles" to grant asylum.

"It's not a blanket policy to aggravate American sensibilities," he said. "In the case of Shakur, they characterize her as a civil rights activist."

Critics contend that is a distortion of the case in which Foerster was gunned down while providing backup for a trooper who had pulled over a 1965 Pontiac LeMans for a faulty taillight.

According to police, Shakur and two men in the car were armed. She fired the first shot, was wounded and kept firing through an ensuing gun battle until Foerster was dead and Trooper James Harper was wounded. Also killed in the shootout: Shakur's brother-in-law, Zayd Malik Shakur.

Washington lawyer Douglas McNabb, an expert on international criminal defense and extradition, said Shakur's safe haven in Cuba seems secure.

"While it is unfortunate that there were deaths, and she was able to break out of prison and make her way to Cuba," the extradition treaty between the U.S. and Cuba - signed in 1905, supplemented in 1926, and still in force - unequivocally protects her, he said.

"One basis for the denial of extradition is political," McNabb said. "Cuba determined her conviction was political."

"I can say [her extradition] is off the table," Gustavo Machin, the deputy director for American affairs at the Cuban Ministry of Foreign Affairs, told Yahoo News, according to a March report on the website the Root.

Playing devil's advocate, McNabb speculated: "Could Cuba, as a sovereign state, reverse its position and decide that having a relationship with the U.S. is more important than not extraditing her? It certainly could."

Latner thinks that is highly unlikely.

"Granted, Cuba is in a state of flux, of change," he said, "but there is no indication, based on any current or past actions, that it would acquiesce on this issue.

"She is maligned in the law enforcement community, but in Cuba she is a folk hero who stood up to antiblack state violence, triumphed, and got away."