Alexandria artist Anthony John Ranfone, found dead dead Tuesday with his two children in what police said was a double murder-suicide, had vowed that his estranged wife would not regain custody of their children, neighbors said yesterday.

Ranfone, who worked for the Department of Energy, had custody of the children from Thanksgiving until Sunday, when they were supposed to be returned to their mother's home in New Jersey. Police discovered the bodies of Ranfone, 36, and David, 4, and Christina, 7, in the family's Datsun sedan, locked in the garage next to the Ranfone home at 17 W. Caton Ave.

All died of carbon monoxide poisoning.

"He wanted to keep those children of his," said Charles Walls, a neighbor who recalled that the artist discussed his wife in their last conversation. "He told me his wife was seeing her old college boyfriend, and that he talked to the boyfriend . . . . He said she would never get the kids . . . . "

Other neighbors recalled that Ranfone had been despondent since he and his wife had separated earlier this year. "The man had emotional problems," said Myron Alber. "I know he had problems that he was sharing with neighbors. But this . . . . "

According to Alexandria Circuit Court records, Karen Boucher Ranfone sued her husband for divorce Sept. 2. She had separated from him in August and was living with relatives in New Jersey, according to the suit.

In the divorce action, Karen Ranfone charged that her husband had been "guilty of cruelty" and had for some time "physically abused, threatened, humiliated and degraded" by subjecting her to "his violent and uncontrolled fits of temper." Ranfone denied the charges and accused her of deserting the family.

Lawyers for Karen Ranfone had filed a request in the court for records of the husband's 1977 stay in Alexandria Hospital, a hospitalization they said was for psychiatric care. Anthony Ranfone was ordered to appear at a hearing Dec. 22 to begin working out details of child custody and financial support. Court records were not clear as to what happened at the session and lawyers for both sides could not be reached for comment yesterday.

Carol Cooper, who lives two doors from the Ranfones and was close to Karen Ranfone, said when she didn't see her neighbor's car in the driveway Sunday, she assumed Anthony Ranfone was returning the children to their mother.

"The children were looking forward to seeing their mother for the holidays," Cooper said. "They really loved both their parents. There was no ogre in this."