The Women's March has received heavy criticism for sending a birthday tweet to a fugitive convicted of murdering a New Jersey state trooper.

A tweet went out Sunday, saying, in part "Happy birthday to the revolutionary #AssataShakur!"

Shakur, whose real name is Joanne Chesimard, was convicted in the 1973 murder of New Jersey State Trooper Werner Foerster. She escaped prison after her conviction and fled to Cuba, where it is believed she still resides.

New Jersey Police Union President Pat Colligan says that the Women’s March honoring of Chesimard is a slap in the face.

“It was just an irresponsible, incredible tweet to put out,” he says. “Celebrating a convicted killer's birthday and then never talking about her real past.”

Chesimard was part of the Black Nationalist group The Black Liberation Army. Police say that Chesimard and two others were pulled over for a broken taillight on the New Jersey Turnpike. A shootout took place during that traffic stop. Chesimard shot Trooper Foerster in the head twice with his own gun.

"It infuriated me. The real hero is Werner Foerster's wife, who raised a 3-year-old son by herself 44 years ago. She should be a hero,” Colligan says.

Chesimard has become a folk hero to some groups like Black Lives Matter, which quotes Chesimard on their website.

The Women’s March backtracked slightly in a series of tweets Monday saying that they do not follow Chesimard’s “militant approach.”

But some Women’s March supporters say that while they don’t agree with the way the group recognized Chesimard, they still think she should be considered an activist for civil rights.

“I get why they want to say ‘Happy Birthday,’” says Women’s March supporter George Epps. “Not really congratulate her but just make her name known again or put back it back out in the media. Because women’s rights is a big deal.”

The New Jersey chapter of the Women’s March declined to comment on the national office’s tweets.