New Jersey Governor Chris Christie wants to ground flights from his state to Cuba.

The reason? He wants a woman convicted of killing a state trooper extradited to the United States.

“It is unacceptable to me as Governor to have any flights between New Jersey and Cuba until and unless convicted cop-killer and escaped fugitive Joanne Chesimard is returned to New Jersey to face justice,” Christie wrote in the letter sent to Port Authority of New York and New Jersey Chairman John Degnan.

“I will not tolerate rewarding the Cuban government for continuing to harbor a fugitive.”

The incident he’s referring to took place about four decades ago. Chesimard was convicted of the murder of Werner Ferster in 1977. The killing took place in 1973.

Chesimard fled to Cuba before she began her life sentence, and has been living in the country ever since under an assumed name.

Dengen has responded, saying,

“I understand Gov. Christie’s strongly expressed concerns and will commence an immediate review of the agency’s role in the proposed flight between Newark and Cuba. I expect that review will be completed in a matter of days.”

United Airlines, who is looking to begin flights from Newark to Cuba, appears to have rejected Christie’s plea, saying,

“We remain very interested in serving Cuba as soon as we are able to do so, and believe United’s service would benefit the airport and the region.”

In other Christie news, he also got in on the “Back to the Future Day” “fun” with a tweet about Social Security spending.

Great Scott! #BackToTheFutureDay (Let's go @Mets!) pic.twitter.com/hnfjIbEwcD

— Chris Christie (@ChrisChristie) October 21, 2015