BALTIMORE, OCT. 30 -- Police said they found a missing Baltimore baby at a Philadelphia homeless shelter today and arrested a woman there suspected of abducting him in June from the Johns Hopkins Hospital maternity ward here.

Authorities said that while lab tests will be required for positive identification, they believe the child is Kendol B. Kernes. He was in good condition today, they said.

FBI officials said they arrested Dorothy Jean Brown, 44, a Baltimore Art Museum security guard, and charged her with kidnaping. Earlier today, Baltimore police arrested Brown's boyfriend, Tony Gilmore, 31, and charged him with being an accessory after the fact.

The Kernes baby was kidnaped from his bassinet in the maternity ward of Johns Hopkins Hospital June 18, two days after he was born, while his mother Patricia Nixon, 21, slept in the same room.

The kidnaping took place one week after 3-week-old Jeremiah Thate was abducted from his crib at Prince George's Hospital Center, and, coincidentally, they both were found within two days. Jeremiah was discovered living in a rat-infested Southeast Washington apartment Wednesday and was returned to his parents, and Kendol was found in a shelter in a low-income section of Philadelphia.

Nixon and Kendol's father, Keith Kernes, 21, who are employed in fast-food restaurants, were in seclusion this evening awaiting the results of blood tests that could prove the baby is theirs. But their lawyer said the family was "elated, hopeful and anxious . . . . They are convinced this is their son -- and given the circumstances, I think the odds are about 100 percent that it is."

When Baltimore police telephoned to tell them a baby was found, the lawyer, Richard V. Falcon, said their first words were: "Thank God."

However, the ordeal is not over for the Nixon and Kernes, who Falcon said had been living "almost like zombies" during the past four months. The baby believed to be Kendol Kernes cannot be returned to his parents until the test results are final, which could take between 24 and 70 hours, Falcon said.

Falcon said that last week he received an anonymous telephone tip that a woman identified as Brown had a baby that was not hers. Police interviewed Brown last Saturday and asked her to report for a blood test on Monday.

However, Gilmore telephoned police Monday morning and told them Brown had left their apartment with the baby on Sunday and had not returned, Baltimore police spokesman Dennis S. Hill said.

Wayne Davis, special agent in charge of the FBI Philadelphia office, said authorities believe that Brown called the baby Tony Gilmore Jr. and that she wanted the baby in order to keep alive her relationship with her boyfriend, United Press International reported.

Baltimore FBI spokesman Andy Manning said city police and FBI agents interviewed relatives, which "pretty well established that she never had the baby" and had fled to relatives in Philadelphia.

FBI agents in Philadelphia combed the city, interviewing still more relatives, Manning said.

"We were like one step behind her," he said. " . . . She was hopping around from one place to another."

Finally, he said, agents found a cabdriver who remembered taking a woman of Brown's description from one of the relatives' homes to a place in West Philadelphia called the Pentacostal Bridegroom Shelter for the homeless, run by a pentacostal church.

Agents went to the shelter at 4 p.m. today, Manning said, and found Brown and a baby there. She was arrested without incident, he said, and the baby was taken into custody for blood tests.

"They'd never given up hope," Falcon said. "They were always positive that they were going to get their baby back . . . . They have been waiting and waiting and waiting. Their lives have been on hold. Obviously, the developments of the last week have been an emotional roller-coaster."

Police said Brown was not a prime suspect until she disappeared. They said several people they interviewed claimed they had seen her pregnant, and that the baby appeared to be well cared for and living in a clean apartment before going to the shelter.

Baltimore FBI spokesman Andy Manning said police interviewed Brown and several of her relatives. The relatives "lied to the police," Manning said, assuring them that the baby was Brown's and that she had given birth to him at home.

According to a statement filed in District Court here, Gilmore told them he was the baby's father, had taken Brown for several prenatal examinations, and had driven Brown and the baby home from Sinai hospital the same day the child was born. Gilmore also told police that Brown had a stillborn baby at Sinai last year.

However, police said there was no record of the birth or the stillbirth at the hospital. The statement said medical records concluded it was unlikely Brown could ever become pregnant.

Ann Allston Boyce, deputy director for administration at the Baltimore Museum of Art, said Brown had been "a very responsible museum guard" for almost 13 years, "and from casual appearance, it certainly wasn't obvious that she was pregnant."

Gilmore was being held in the Baltimore jail yesterday, with bond set at $100,000.

Brown was ordered held without bond in the Philadelphia House of Correction, pending a hearing next week.