A 40-year-old Takoma Park man apparently killed his 78-year-old mother and then himself yesterday, Montgomery County police said.

Helene Louise Mackall was found lying face down on her bed in her one-bedroom apartment in the Leisure World development community for senior citizens in Silver Spring at about 10:30 a.m., according to police spokesman Sgt. Harry Geehreng. He said that Mackall, who appeared to have been killed Sunday night, had head and facial injuries caused by blunt force such as bare fists.

Two detectives went to the Takoma Park home where the woman's son, Alan James Mackall, lived and knocked at the front door at about 3:30 p.m. While they were waiting for their knock to be answered, they heard a gunshot, Geehreng said. He said that Alan James Mackall was found inside, dead of an apparent self-inflicted shotgun wound to the head.

"We are calling it an apparent murder-suicide," Geehreng said.

One neighbor said that Alan Mackall was apparently separated from his wife and unemployed. Addessa Burnett, who lives next door, said that the Mackalls had bought the house at 1108 Jackson Ave. about 16 months ago. But Mackall has been living in the home alone for three to four months, Burnett said.

Burnett said that Helene Mackall had visited her son as recently as two weeks ago. "She was here and I saw her drive away," Burnett said.

The mother has been living at the Leisure World complex at 15101 Interlachen Rd. for at least two years, according to friends there, and appeared to be in good health for her age.

"I think she had been ill before -- a stroke maybe," said Ruth Richards, who lived in the same building as Mackall. "You could tell because of her speech -- it took a long time for her to tell you what she wanted to tell you."

Neighbors in the 10-story high-rise building where Helene Mackall lived became worried about her yesterday when she failed to retrieve the morning newspaper from outside her door, Geehreng said. He said that two neighbors went inside to check on Mackall, found her dead and notified police.

"We think the son was the last person to see her alive," Geehreng said.