A Northeast man who was sent to St. Elizabeths Hospital for a mental evaluation after holding police at bay in a barricade situation last month was arrested early yesterday in the strangling of a top aide in Mayor Marion Barry's reelection campaign.

D.C. police said Kenneth Dion Hubbard, 25, of 4832 Queens Chapel Ter. NE, was charged with felony murder at 1:30 a.m. after questioning in an intense, around-the-clock police investigation that started when firefighters discovered Peggy Russell Gee, 55, early Saturday in the dining room of her ransacked and burning residence at 4209 18th St. NE.

Hubbard, who was being held in the central cell block at police headquarters yesterday, is expected to be arraigned on the charge today in D.C. Superior Court, according to Deputy Chief Alfonso Gibson, commander of the criminal investigations division. The fire, which caused $25,000 damage to the house, was ruled arson.

At a news conference, Gibson released few details of the killing, citing a continuing investigation. But he said the arrest was made after Hubbard gave statements containing "discrepancies" during a police interview. Gibson said that the slaying of Gee, who scheduled campaign events for Barry, had no connection with the mayor's campaign and that the motive appeared to be robbery.

"We did collect certain physical evidence that led us to the individual," Gibson said, adding that Gee did not have a personal relationship with Hubbard but had had contact with him on at least one occasion. Gee, who police said was strangled manually, lived a few blocks from Hubbard.

"Her contact with him is some of the critical evidence that is going to be revealed in the trial," Gibson said. The police official said Gee had had a conversation with Hubbard "on a prior occasion" but declined to comment further.

Josephine Johnson, a neighbor of Gee, said that two weeks ago a man who said he lived on Queen's Chapel Terrace NE appeared on Gee's block with Gee's golden retriever, Sunrise, who had been missing for several days. Johnson said the man told her that he had found the dog, had taken good care of it and deserved a reward.

Johnson said she wrote down the man's name and address and passed the information along to Gee. In an interview yesterday, Johnson said she could not recall the man's name for certain but was sure that he lived on Queen's Chapel Terrace, where Hubbard resides. Johnson said that last week another neighbor spotted the man returning the dog a second time.

Jack S. Russell, Gee's brother, and Anita Bonds, Barry's campaign manager and Gee's boss, said Gee had expressed concern about the dog and a man's demand for a reward. Police would not comment on the details involving the dog.

The barricade incident involving Hubbard occurred May 29 when Hubbard allegedly threatened to kill a locksmith who had been called to the Queens Chapel Terrace residence by Hubbard's brother to repair locks that had been damaged by Hubbard, police said.

Officers of the police special operations division used tear gas to force Hubbard from the house in the early morning hours of the next day, but no weapon was found and police decided not to charge him. Hubbard was sent instead to St. Elizabeths for a mental evaluation, according to a statement issued by the police.

An autopsy on Gee, who was found under the dining room carpet, has not been completed, police said. Until tests are finished, it cannot be determined whether Gee was sexually assaulted, Gibson said. Neighbors said a broken basement window in the rear of the house appeared to indicate that Gee's assailant had entered the residence forcibly.

Bonds said that on Friday Gee had expressed concern about her dog, recalling that the animal had disappeared several times in recent weeks and had apparently been returned a second time on Tuesday or Wednesday by the man who had previously demanded a reward.

"She was telling me about this," Bonds recalled. Bonds said she suggested that Gee give the man the dog but that Gee had replied that she did not think that the man was "right."

"She had a feeling about him," Bonds said.

Gee, a native of Rural Retreat, Va., moved to this area in 1948 and worked as a nurse at the old Freedmen's Hospital and Walter Reed Army Hospital and as administrator at a city-operated medical clinic. Before becoming Barry's campaign scheduling aide this year, she served in his mayoral campaigns in 1978 and 1982 and also worked in the presidential campaign of Jesse Jackson.

Bonds described Gee as a level-headed adminstrator and a "citizen type" who involved herself in community activities, was well-informed and enjoyed working in political campaigns after her retirement from nursing about 1979.

Bonds, a key Barry aide who was a top official in his last campaign, said Gee's last day at work on Friday was notable because of her references to her dog and her frustration over a detail of the mayor's campaign in one of the city's wards.

"I could depend on her. I knew she was available," said Bonds, describing Gee as a personal friend whom she had met shortly before the 1978 campaign. "She was your citizen type who practiced what she preached -- very much the type of person who was concerned with how her tax dollars were being spent."

Gee, who was divorced from Wallace W. Gee, had a son named Michael and daughter named Kimberly, Bonds said.

Staff Writer Richard Pearson contributed to this report.