The FBI has made the fugitive member of a black militant group convicted of murdering a US state trooper, now living in Cuba, the first woman to feature on its list of most wanted terrorists.
The reward for the capture and return of Joanne Chesimard, now living as Assata Shakur, has been doubled to $2m (€1.52m).
The move comes on the 40th anniversary of the bloody gun battle.
New Jersey State Police Superintendent Col Rick Fuentes said at a news conference: "She continues to flaunt her freedom in the face of this horrific crime."
The US Justice Department has offered a $1m (€762,000) reward for information leading to her capture.
The additional money is being put up by the state of New Jersey.
Chesimard is a member of the violent Black Liberation Army.
She was convicted of the 1973 murder of Werner Foerster during a traffic stop.
The BLA was responsible for killing more than a dozen police officers in the 1970s and 1980s, agent Aaron Ford of the FBI's Newark division said.
According to police, Foerster and his partner stopped a car carrying Chesimard and two others for a broken tail light.
When the troopers approached the car, a gunfight ensued and both troopers were injured.
Chesimard then took Foerster's gun and shot him twice in the head as he lay on the ground.
She was convicted in 1977 but escaped from prison in November 1979 with the help of accomplices.
She spent the next few years living in safe houses before surfacing in Cuba in 1984, Col Fuentes said.
In Cuba, Chesimard has continued to espouse her anti-US views in speeches advocating "revolution and terrorism".
It is thought that she may have connections to other international terrorist organisations, Mr Ford said.
Chesimard is believed to be one of dozens of US fugitives living in Cuba, many of them one-time members of militant groups.
Cuba does not have an extradition agreement with the US because of the chilly relations between the two countries over the last five decades, but the climate appears to be slowly changing.
In recent years, Cuba has deported some fugitives back to the US, including one man convicted of mail fraud and another sought on child pornography charges.
This month, the country returned a Florida couple accused in a custody dispute of kidnapping their two children and sailing to Cuba.
The Cuban government had no immediate comment on yesterday's announcement.
This week, the State Department said it has no plans to remove Cuba from a list of state sponsors of terrorism that also includes Iran, Syria and Sudan.
Cuba has denied links to terrorism.