HAVERSTRAW, N.Y. (CBSNewYork) — Police in Rockland County were asking for help Monday in a manhunt dating back three years.

As CBS2’s Lou Young reported, Eugene Palmer is wanted in the murder of his daughter in law in Haverstraw in September 2012. He disappeared after the shooting and a massive manhunt followed in Harriman State Park, but police believe he is still alive.

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“We have no reason to believe he’s dead,” said Haverstraw police Detective Sgt. George Lutz. “As a matter of fact, we believe he’s alive.”

Three years later, the story is well-known. Neighbor Doug Jobson said Palmer is now “unfortunately” a local legend.

The murder scene is a tranquil family compound alongside a stream on Willow Grove Road. Tammy Palmer was divorcing Eugene Palmer’s son, and paid for it with her life, according to police.

“He shot her in cold blood,” Lutz said. “She attempted to flee on foot. He chased her down like a dog and shot her again, and killed her.”

The experienced hunter and outdoorsman apparently planned the shooting for days – stopping by his sister’s house after the crime.

“He says: ‘Here’s my money. Pay my taxes. I’ve had enough. I just shot and killed Tammy. And give me about an hour to get away, and then call the cops and do whatever you have to do,” said Eugene Palmer’s sister, Elaine Palmer Babcock.

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Police found Palmer’s truck at the edge of the vast Harriman State Park, but Palmer himself vanished. Many figured winter in the woods would kill him.

The park is all rugged terrain, but it is also heavily used. Three summers and tens of thousands of visitors have come and gone since Palmer disappeared.

If Palmer’s body were at the park, police said they are sure someone would have found it by now.

Many who know Palmer feel the same way, but refused to talk on camera because they were afraid.

“We’re never going to be done with it until we find him one way or another — dead or alive,” Lutz said. “We believe there are people who are helping him. We don’t think he could’ve done it by himself. We believe he’s alive, and he could be anywhere.”

Those who know Palmer best – his family – were not talking at all Monday.

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Last year, a judge awarded the value of Palmer’s estate – estimated at $2 million in property – to his grandchildren as compensation for the death of their mother.