"There is no statute of limitations on her crime," said Col. Rick Fuentes, superintendent of the New Jersey State Police. "No matter how long it takes, we will employ every legal option to bring her back to the justice she will face in a United States prison."
In 1977, Chesimard was convicted of felony murder for her role in the execution-style killing of Trooper Werner Foerster.
Last year, New Jersey officials increased the reward for her capture to $1 million. The state police Internet home page still features a flashing red light next to Chesimard's picture and an announcement of the reward.
The Department of Homeland Security has added Chesimard, now 58, to the list of the nation's most wanted terrorists for her activities with the Black Liberation Army before Foerster's slaying.
"This is and will always be a priority," said State Police Lt. Kevin Tormey, who has been in charge of the Chesimard investigation for 17 years. "You talk to any cop anywhere in the country about this case, and you tell them it happened in 1973, they'll still drop everything to help."
Philadelphia's only other unsolved police killing - the 1970 slaying of Officer Frederick Cione - also is regularly reviewed by homicide investigators. But there remains no suspect.
The Chesimard reward generated a "spike of interest" from bounty hunters across the country, Tormey said. But Chesimard, who escaped from the state women's prison in Clinton with the help of four friends, fled to Cuba in the mid-1980s.
Tormey's work is devoted to getting Chesimard back to the United States and having her finish her prison sentence of life plus 26 years.
On May 2, 1973, Chesimard was the front-seat passenger in a Pontiac LeMans heading south on the New Jersey Turnpike. She was traveling to Philadelphia or Washington with two other members of the Black Liberation Army, an organization that advocated the overthrow of the U.S. government and the killing of police officers.
According to evidence at her trial, Trooper James Harper spotted a broken taillight and pulled the Pontiac over about 200 yards from state police headquarters, then in East Brunswick.
"The trooper had no idea who he was stopping," Tormey said. "All three were carrying fictitious identification and were armed."
Soon, Foerster arrived as backup.
Harper became suspicious when the driver, Clark Squire, could not say who owned the Pontiac, which had Vermont plates. Foerster frisked Squire and found a fully loaded .380-caliber ammunition clip in his pocket.
Seconds later, Chesimard opened fire with a 9mm pistol, hitting Harper in the shoulder. She squeezed off two more shots at Foerster as she scrambled out of the car.
Harper shot Chesimard twice. She collapsed to the ground.
Foerster was on the ground behind his cruiser, his arm broken by a slug from Squire's .380, as Harper ran to headquarters for help.
It's unclear what happened after that. But somebody who had been riding in the car fired two shots into Foerster's skull.
"They used his own service revolver. He was incapacitated," Tormey said with a shiver of disgust. "They could have left him. But that was the signature of the Black Liberation Army."
Chesimard and Squire were arrested five miles down the turnpike.
Chesimard has written an autobiography, which is available on the Internet. "But in her story she conveniently eliminates her gun," Tormey said.
Tormey said the big reward wasn't meant to attract bounty hunters.
"For starters, we don't want some cowboy going down there and killing her or killing Cubans," he said. "But if someone can broker a deal with Castro or some independent, freethinking Cuban could arrange for her to take a boat ride into international waters, we would not be averse to it. The key thing is no one gets harmed, including her."
Tormey said there had been an all-out effort to spread word of the Chesimard reward. Troopers have addressed the Cuban exile community in Miami and distributed flyers and wanted posters throughout the Caribbean and Central America.
The Cuban government considers Chesimard, who now goes by the name Assata Shakur, a political exile and gives her a stipend, a home, Internet access, food and gas, Tormey said.
She has moved several times in Havana. "We've come up with a street address a few times," Tormey said.
Soon after the increased reward was announced, the Cuban government stepped up security around Chesimard's home, Tormey said.
"She lives better than any other fugitive in Cuba," he said, "but it's not much of a life. The longer she's down there, the more it's like she's in prison anyway. She's very restricted."
He added: "As long as there's a New Jersey State Police, we'll have someone assigned to this case, and eventually we'll bring her in."
Contact staff writer Sam Wood at 856-779-3838 or firstname.lastname@example.org.